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  1. Agricultural Development, Land Change, and Livelihoods in Tanzania's Kilombero Valley

    NASA Astrophysics Data System (ADS)

    Connors, John Patrick

    The Kilombero Valley lies at the intersection of a network of protected areas that cross Tanzania. The wetlands and woodlands of the Valley, as well as the forest of surrounding mountains are abundant in biodiversity and are considered to be critical areas for conservation. This area, however, is also the home to more than a half million people, primarily poor smallholder farmers. In an effort to support the livelihoods and food security of these farmers and the larger Tanzanian population, the country has recently targeted a series of programs to increase agricultural production in the Kilombero Valley and elsewhere in the country. Bridging concepts and methods from land change science, political ecology, and sustainable livelihoods, I present an integrated assessment of the linkages between development and conservation efforts in the Kilombero Valley and the implications for food security. This dissertation uses three empirical studies to understand the process of development in the Kilombero Valley and to link the priorities and perceptions of conservation and development efforts to the material outcomes in food security and land change. The first paper of this dissertation examines the changes in land use in the Kilombero Valley between 1997 and 2014 following the privatization of agriculture and the expansion of Tanzania's Kilimo Kwanza program. Remote sensing analysis reveals a two-fold increase in agricultural area during this short time, largely at the expense of forest. Protected areas in some parts of the Valley appear to be deterring deforestation, but rapid agricultural growth, particularly surrounding a commercial rice plantation, has led to loss of extant forest and sustained habitat fragmentation. The second paper focuses examines livelihood strategies in the Valley and claims regarding the role of agrobiodiversity in food security. The results of household survey reveal no difference or lower food security among households that diversify their

  2. Interpreting characteristic drainage timescale variability across Kilombero Valley, Tanzania

    NASA Astrophysics Data System (ADS)

    Lyon, S. W.; Koutsouris, A.

    2013-12-01

    We derived the characteristic drainage timescale (K) from river discharge records across the Kilombero Valley in central Tanzania to explore seasonal variability and spatiotemporal patterns in dominant hydrologic processes. This was done using streamflow recession analysis to isolate storage-discharge relationships drawing from hydraulic groundwater theory. Such an approach may be advantageous in this and other data limited environments as it allows utilization of streamflow records with large time gaps and limited consistency. The observed K values during the wet season and for the relatively smaller catchments draining upland positions are consistent with those expected from hydraulic groundwater theory (e.g., K = 45 × 15 days). In the dry season, however, the timescales estimated for these catchments are larger than expected from hydraulic groundwater theory. Further, larger catchments draining part of the valley bottom, which is dominated by wetlands, never exhibited K values consistent with those expected from hydraulic groundwater theory. These hydrometric results are consistent with initial hydrologic tracer investigations with implications for the transit times of water moving through this upland-wetland seasonally-connected region and resultant regional groundwater recharge. Identifying these spatiotemporal shifts (i.e., isolating when general hydraulic groundwater theory may not be valid) facilitates process representation relevant for improved hydrologic modeling and water resources management in regions like Kilombero Valley.

  3. Capturing and Explaining Preference Heterogeneity for Wetland Management Options in the Kilombero Valley, Tanzania

    NASA Astrophysics Data System (ADS)

    Speelman, Stijn; Mombo, Felister; Vandermeulen, Valerie; Phillip, Damas; Van Huylenbroeck, Guido

    2015-01-01

    Wetland degradation has recently received considerable research attention. Although wetlands are valuable ecosystems, their actual value is difficult to measure because the services they provide often do not have market values. The current study seeks to investigate the preferences for wetland management options in the Kilombero Valley, central Tanzania using choice modeling. The results show that both respondents from the Kilombero Valley and Morogoro Municipality desire improvements in the condition of the wetlands. This indicates that the ongoing degradation is not socially optimal. A second finding is that the preferences for wetland conservation are heterogeneous and can be linked to livelihood characteristics. Communities living in the area, for example, are highly dependent on the wetland for their livelihood and would be impacted by conservation measures. Therefore, in order to reduce the pressure on wetlands, it is necessary and imperative to explore the options for alternative income-generating activities or to focus, for example, on technologies to improve efficiency and effectiveness in crop production.

  4. Capturing and explaining preference heterogeneity for wetland management options in the Kilombero Valley, Tanzania.

    PubMed

    Speelman, Stijn; Mombo, Felister; Vandermeulen, Valerie; Phillip, Damas; Van Huylenbroeck, Guido

    2015-01-01

    Wetland degradation has recently received considerable research attention. Although wetlands are valuable ecosystems, their actual value is difficult to measure because the services they provide often do not have market values. The current study seeks to investigate the preferences for wetland management options in the Kilombero Valley, central Tanzania using choice modeling. The results show that both respondents from the Kilombero Valley and Morogoro Municipality desire improvements in the condition of the wetlands. This indicates that the ongoing degradation is not socially optimal. A second finding is that the preferences for wetland conservation are heterogeneous and can be linked to livelihood characteristics. Communities living in the area, for example, are highly dependent on the wetland for their livelihood and would be impacted by conservation measures. Therefore, in order to reduce the pressure on wetlands, it is necessary and imperative to explore the options for alternative income-generating activities or to focus, for example, on technologies to improve efficiency and effectiveness in crop production. PMID:25403812

  5. Factors determining the choice of hunting and trading bushmeat in the Kilombero Valley, Tanzania.

    PubMed

    Nielsen, Martin Reinhardt; Jacobsen, Jette Bredahl; Thorsen, Bo Jellesmark

    2014-04-01

    Regulation of illegal bushmeat trade is a major conservation challenge in Africa. We investigated what factors are most likely to induce actors in the bushmeat trade to shift to an alternative occupation by conducting a choice experiment with 325 actors in the bushmeat trade in the Kilombero Valley, Tanzania. Specifically, we asked respondents to choose between hunting or trading bushmeat and alternative salary-paying work, in a set of hypothetical scenarios where the attributes of these alternatives were varied and included measures of command and control, price of substitute meat, daily salary in the work option, and whether or not cows were donated to the respondent. We modeled the choice contingent on socioeconomic characteristics. The magnitude of fines and patrolling frequency had a significant but very low negative effect on the probability of choosing to engage in hunting or trading bushmeat compared with the salary of an alternative occupation. Donation of livestock and the price of substitute meats in the local market both affected the choice significantly in a negative and a positive direction, respectively. The wealthier a household was the more likely the respondent was to choose to continue hunting or trading bushmeat. On the margin, our results suggest that given current conditions in the Kilombero Valley on any given day 90% of the respondents would choose salary work at US$3.37/day over their activities in the bushmeat trade, all else equal.

  6. Livelihoods in the wetlands of Kilombero Valley in Tanzania: Opportunities and challenges to integrated water resource management

    NASA Astrophysics Data System (ADS)

    Kangalawe, Richard Y. M.; Liwenga, Emma T.

    Wetlands contribute in diverse ways to the livelihood of many people in Africa. One of the major constraints to the wise use of African wetlands is lack of knowledge by planners and natural resource managers on the benefits that they provide and techniques by which they can be utilised in a sustainable manner. This paper presents findings from a study undertaken in Kilombero Valley, Tanzania, on the dynamics and benefits of natural resource use in the wetlands. The paper specifically focuses on opportunities and challenges related to integrated water resource management. The study was conducted in two villages, Idete and Signali located in Kilombero District, Morogoro Region. Participatory assessment and household interviews were employed to obtain both qualitative and quantitative information, respectively, pertaining to biophysical, agronomic and socio-economic facts that influence community access to, and utilisation of the wetland resources. The findings show that Kilombero Valley has high potential for a diversity of livelihood activities. The wetland also serves as a source of water for farming, livestock, fishing and for domestic uses. Over the last two decades the use of wetlands for agriculture has increased because of increasing population of both pastoral and agro-pastoral communities, and hence the resultant need to produce more food. However, there are environmental concerns associated with increasing use of wetlands for agriculture and other livelihood activities, including deforestation and trampling of soils by increasing livestock numbers, increased demand on the water resources and lack of elaborate institutional framework to facilitate the integration of the various sectoral and cross-sectoral uses of the wetland resources and among stakeholders. The main conclusion is that sustainable livelihood development of wetland communities requires multidisciplinary and integrated efforts in addressing constraints in the various sectors such as

  7. Inter-epidemic Transmission of Rift Valley Fever in Livestock in the Kilombero River Valley, Tanzania: A Cross-Sectional Survey

    PubMed Central

    Sumaye, Robert D.; Geubbels, Eveline; Mbeyela, Edgar; Berkvens, Dirk

    2013-01-01

    Background In recent years, evidence of Rift Valley fever (RVF) transmission during inter-epidemic periods in parts of Africa has increasingly been reported. The inter-epidemic transmissions generally pass undetected where there is no surveillance in the livestock or human populations. We studied the presence of and the determinants for inter-epidemic RVF transmission in an area experiencing annual flooding in southern Tanzania. Methodology A cross-sectional sero-survey was conducted in randomly selected cattle, sheep and goats in the Kilombero river valley from May to August 2011, approximately four years after the 2006/07 RVF outbreak in Tanzania. The exposure status to RVF virus (RVFV) was determined using two commercial ELISA kits, detecting IgM and IgG antibodies in serum. Information about determinants was obtained through structured interviews with herd owners. Findings An overall seroprevalence of 11.3% (n = 1680) was recorded; 5.5% in animals born after the 2006/07 RVF outbreak and 22.7% in animals present during the outbreak. There was a linear increase in prevalence in the post-epidemic annual cohorts. Nine inhibition-ELISA positive samples were also positive for RVFV IgM antibodies indicating a recent infection. The spatial distribution of seroprevalence exhibited a few hotspots. The sex difference in seroprevalence in animals born after the previous epidemic was not significant (6.1% vs. 4.6% for females and males respectively, p = 0.158) whereas it was significant in animals present during the outbreak (26.0% vs. 7.8% for females and males respectively, p<0.001). Animals living >15 km from the flood plain were more likely to have antibodies than those living <5 km (OR 1.92; 95% CI 1.04–3.56). Species, breed, herd composition, grazing practices and altitude were not associated with seropositivity. Conclusion These findings indicate post-epidemic transmission of RVFV in the study area. The linear increase in seroprevalence in the post

  8. Antenatal care in practice: an exploratory study in antenatal care clinics in the Kilombero Valley, south-eastern Tanzania

    PubMed Central

    2011-01-01

    Background The potential of antenatal care for reducing maternal morbidity and improving newborn survival and health is widely acknowledged. Yet there are worrying gaps in knowledge of the quality of antenatal care provided in Tanzania. In particular, determinants of health workers' performance have not yet been fully understood. This paper uses ethnographic methods to document health workers' antenatal care practices with reference to the national Focused Antenatal Care guidelines and identifies factors influencing health workers' performance. Potential implications for improving antenatal care provision in Tanzania are discussed. Methods Combining different qualitative techniques, we studied health workers' antenatal care practices in four public antenatal care clinics in the Kilombero Valley, south-eastern Tanzania. A total of 36 antenatal care consultations were observed and compared with the Focused Antenatal Care guidelines. Participant observation, informal discussions and in-depth interviews with the staff helped to identify and explain health workers' practices and contextual factors influencing antenatal care provision. Results The delivery of antenatal care services to pregnant women at the selected antenatal care clinics varied widely. Some services that are recommended by the Focused Antenatal Care guidelines were given to all women while other services were not delivered at all. Factors influencing health workers' practices were poor implementation of the Focused Antenatal Care guidelines, lack of trained staff and absenteeism, supply shortages and use of working tools that are not consistent with the Focused Antenatal Care guidelines. Health workers react to difficult working conditions by developing informal practices as coping strategies or "street-level bureaucracy". Conclusions Efforts to improve antenatal care should address shortages of trained staff through expanding training opportunities, including health worker cadres with little pre

  9. Hydrothermal system in Southern Grass Valley, Pershing County, Nevada

    SciTech Connect

    Welch, A.H.; Sorey, M.L.; Olmsted, F.H.

    1981-01-01

    Southern Grass Valley is a fairly typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163 to 176/sup 0/C. Results of geologic, hydrologic, geophysical and geochemical investigations are discussed in an attempt to construct an internally consistent model of the system.

  10. Magnetotelluric Data, Southern San Luis Valley, Colorado

    USGS Publications Warehouse

    Williams, Jackie M.; Rodriguez, Brian D.

    2007-01-01

    Introduction The population of the San Luis Valley region is growing rapidly. The shallow unconfined and the deeper confined Santa Fe Group aquifer in the San Luis Basin is the main sources of municipal water for the region. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal ground-water aquifers. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin located in southern Colorado. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey, called magnetotellurics (MT), and hydrologic and lithologic data are being used to better understand the aquifer systems. The primary goal of the MT survey is to map changes in electrical resistivity with depth that are related to differences in rock type. These various rock types help control the properties of aquifers in the region. This report does not include any interpretation of the data. Its purpose is to release the MT data acquired at the 22 stations shown in figure 1.

  11. Surface Deformation in Imperial Valley, Southern California

    NASA Astrophysics Data System (ADS)

    Eneva, M.; Adams, D.; Falorni, G.; Morgan, J.

    2013-12-01

    The Imperial Valley in southern California is subjected to significant tectonic deformation resulting from the relative movement of the North American and Pacific plates. It is characterized by large earthquakes, frequent swarm activity, and aseismic events. High heat flow makes possible the operation of geothermal fields, some of which cause man-made surface displacements superimposed on the tectonic deformation. We apply radar interferometry (InSAR) to analyze Envisat ASAR data for the period 2003-2010. The SqueeSAR technique is used to obtain deformation time series and annual rates at numerous locations of permanent and distributed scatterers (PS and DS). SqueeSAR works very well in agricultural areas, where conventional differential InSAR (DinSAR) fails. We observe differential movements marking the Superstition Hills, San Andreas, and Imperial faults. The Imperial fault traverses agricultural fields, where DInSAR does not work and thus our SqueeSAR observations are the first for this fault (Fig. 1). We also observe steps in the deformation time series around the Superstition Hills fault from an October 2006 aseismic event and the April 2010 M7.2 earthquake south of the U.S.-Mexico border. Significant annual deformation rates are detected in the current geothermal fields. For example, subsidence of up to -50 mm/year is seen at the Salton Sea field (Fig. 2), and both subsidence and uplift are seen at Heber. We also determine the deformation baseline at prospective geothermal fields, thus making it possible in the future to distinguish between man-made and tectonic causes of surface deformation. Fig. 1. Line-of-sight (LOS) deformation indicates differential displacement on both sides of Imperial Fault. Movements away from the satellite are shown in yellow to red, and towards the satellite in blue. Larger deformation is associated with two geothermal fields, Heber (to the south-west) and East Mesa (to the east). Fig. 2. Subsidence in the Salton Sea geothermal

  12. Is It Working? Lysimeter Monitoring in the Southern Willamette Valley Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  13. Model Program: Southern Lehigh High School, Center Valley, PA

    ERIC Educational Resources Information Center

    Colelli, Richard

    2009-01-01

    In this article, the author describes the technology education program at Southern Lehigh High School, Center Valley, Pennsylvania. The school district is presently providing an educational program known for its excellence and forward-looking perspective, which is sensitive to the changing needs of its students. Within the technology education…

  14. Hydrologic Evaluation of the Jungo Area, Southern Desert Valley, Nevada

    USGS Publications Warehouse

    Lopes, Thomas J.

    2010-01-01

    RecologyTM, the primary San Francisco waste-disposal entity, is proposing to develop a Class 1 landfill near Jungo, Nevada. The proposal calls for the landfill to receive by rail about 20,000 tons of waste per week for up to 50 years. On September 22, 2009, the Interior Appropriation (S.A. 2494) was amended to require the U.S. Geological Survey to evaluate the proposed Jungo landfill site for: (1) potential water-quality impacts on nearby surface-water resources, including Rye Patch Reservoir and the Humboldt River; (2) potential impacts on municipal water resources of Winnemucca, Nevada; (3) locations and altitudes of aquifers; (4) how long it will take waste seepage from the site to contaminate local aquifers; and (5) the direction and distance that contaminated groundwater would travel at 95 and 190 years. This evaluation was based on review of existing data and information. Desert Valley is tributary to the Black Rock Desert via the Quinn River in northern Desert Valley. The Humboldt River and Rye Patch Reservoir would not be affected by surface releases from the proposed Jungo landfill site because they are in the Humboldt basin. Winnemucca, on the Humboldt River, is 30 miles east of the Jungo landfill site and in the Humboldt basin. Groundwater-flow directions indicate that subsurface flow near the proposed Jungo landfill site is toward the south-southwest. Therefore, municipal water resources of Winnemucca would not be affected by surface or subsurface releases from the proposed Jungo landfill site. Basin-fill aquifers underlie the 680-square-mile valley floor in Desert Valley. Altitudes around the proposed Jungo landfill site range from 4,162 to 4,175 feet. Depth to groundwater is fairly shallow in southern Desert Valley and is about 60 feet below land surface at the proposed Jungo landfill site. A groundwater divide exists about 7 miles north of the proposed Jungo landfill site. Groundwater north of the divide flows north towards the Quinn River. South of

  15. Paleoseismology of the Southern Section of the Black Mountains and Southern Death Valley Fault Zones, Death Valley, United States

    USGS Publications Warehouse

    Sohn, Marsha S.; Knott, Jeffrey R.; Mahan, Shannon

    2014-01-01

    The Death Valley Fault System (DVFS) is part of the southern Walker Lane–eastern California shear zone. The normal Black Mountains Fault Zone (BMFZ) and the right-lateral Southern Death Valley Fault Zone (SDVFZ) are two components of the DVFS. Estimates of late Pleistocene-Holocene slip rates and recurrence intervals for these two fault zones are uncertain owing to poor relative age control. The BMFZ southernmost section (Section 1W) steps basinward and preserves multiple scarps in the Quaternary alluvial fans. We present optically stimulated luminescence (OSL) dates ranging from 27 to 4 ka of fluvial and eolian sand lenses interbedded with alluvial-fan deposits offset by the BMFZ. By cross-cutting relations, we infer that there were three separate ground-rupturing earthquakes on BMFZ Section 1W with vertical displacement between 5.5 m and 2.75 m. The slip-rate estimate is ∼0.2 to 1.8 mm/yr, with an earthquake recurrence interval of 4,500 to 2,000 years. Slip-per-event measurements indicate Mw 7.0 to 7.2 earthquakes. The 27–4-ka OSL-dated alluvial fans also overlie the putative Cinder Hill tephra layer. Cinder Hill is offset ∼213 m by SDVFZ, which yields a tentative slip rate of 1 to 8 mm/yr for the SDVFZ.

  16. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley's Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 due to nitrate levels in the groundwater ...

  17. 77 FR 47921 - Pecos Valley Permian Railroad, L.L.C. d/b/a Pecos Valley Southern Railway Company-Lease Exemption...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-10

    ... Company--Lease Exemption--Pecos Valley Southern Railway Company Pecos Valley Permian Railroad, L.L.C. d/b... exemption pursuant to 49 CFR 1150.31 to lease from the Pecos Valley Southern Railway Company (PVS) and... states that the lease agreement between PVS and PVR will not contain any interchange commitments....

  18. Analysis of gravity data in Central Valleys, Oaxaca, southern, Mexico

    NASA Astrophysics Data System (ADS)

    Gonzalez, T.; Ferrusquia, I.

    2015-12-01

    The region known as Central Valleys is located in the state of Oaxaca, southern, Mexico (16.3o- 17.7 o N Lat. and 96 o - 97 o W Long.) In its central portion is settled the capital of the state. There are very few published detailed geological studies.. Geomorphological and geological features, indicates that Central Valleys and surrounding mountains conform a graben structure. Its shape is an inverted Y, centred on Oaxaca City. The study area was covered by a detailed gravity survey with a homogenous distribution of stations. The Bouguer gravity map is dominated by a large gravity low, oriented NW-SE. In order to know the characteristics of anomalies observed gravity, data transformations were used. The use of spectral methods has increased in recent years, especially for the estimation of the depth of the source. Analysis of the gravity data sheds light on the regional depth of the Graben basement and the spatial distribution of the volcanic rocks

  19. Quaternary incised valleys in southern Brazil coastal zone

    NASA Astrophysics Data System (ADS)

    Weschenfelder, Jair; Baitelli, Ricardo; Corrêa, Iran C. S.; Bortolin, Eduardo C.; dos Santos, Cristiane B.

    2014-11-01

    High-resolution seismic records obtained in the Rio Grande do Sul coastal zone, southern Brazil, revealed that prominent valleys and channels developed in the area before the installation of actual coastal plain. Landwards, the paleoincisions can be linked with the present courses of the main river dissecting the area. Oceanwards, they can be linked with related features previously recognized in the continental shelf and slope by means of seismic and morphostructural studies. Based mainly on seismic, core data and geologic reasoning, it can be inferred that the coastal valleys were incised during forced regression events into the coastal prism deposited during previous sea level highstand events of the Quaternary. Seismic data has revealed paleovalleys up to 10 km wide and, in some places, infilled with up to 40 m thick of sediments. The results indicated two distinct periods of cut-and-fill events in the Patos Lagoon area. The filling of the younger incision system is mainly Holocene and its onset is related to the last main regressive event of the Pleistocene, when the sea level fell about 130 m below the actual position. The older incision and filling event is related to the previous regressive-transgressive events of the Middle and Late Pleistocene. The fluvial discharge fed delta systems on the shelf edge during the sea level lowstands. The subsequent transgressions drowned the incised drainage, infilling it and closing the inlets formerly connecting the coastal river to the ocean. The incised features may have played a significant role on the basin-margin architecture, facies distribution and accommodation space during the multitude of up and down sea level events of the Quaternary.

  20. Petrology of the Paloma Valley ring complex, southern California batholith

    USGS Publications Warehouse

    Morton, D.M.; Bard, A.M.

    1976-01-01

    The Paloma Valley ring complex is one of the numerous plutons that make up the Cretaceous southern California batholith. The complex is composite, consisting of (1) an older, single ring dike and two subsidiary short-arced inner dikes, and (2) a younger set of thin short-arced dikes largely inside the older ring dike. The older ring dike, composed of granodiorite-quartz monzonite, has nearly vertical walls and is elliptical in plan; its long axis (14 km) is oriented west-northwest. It was emplaced in and contains numerous fragments of gabbro. The more than 200 short-arced granitic pegmatite dikes, mainly ranging from 0.2 to 1 m in thickness, define a domal ring dike set with moderately to steeply dipping outer dikes and nearly horizontal inner dikes. The younger dikes cut both the older ring dike and the gabbro. Spatially associated with the younger dikes are bodies of fine-grained granophyre that contain stringers of granitic pegmatite. The granophyre has an Mg content similar to that of the younger ring-dike rock, but contains less K and more Fe. The older ring dike is interpreted to have been magmatically emplaced in an elliptical zone of ring fracturing in gabbro; the magma made room by stoping the denser gabbro with little assimilation. Upon a release of pressure, a set of domal fractures formed, along which volatile-rich magma was emplaced, forming the younger ring dikes. Granophyre resulted from pressure-quenching through a loss of volatiles. Residual volatiles, or volatiles that were introduced later, recrystallized parts of the granophyre and caused the formation of pegmatite stringers.

  1. Morphological properties of tunnel valleys beneath the southern sector of the former Laurentide Ice Sheet

    NASA Astrophysics Data System (ADS)

    Livingstone, Stephen; Clark, Chris

    2016-04-01

    Tunnel valleys have been widely reported on the bed of former ice sheets and are considered an important expression of subglacial meltwater drainage. Although known to have been cut by erosive meltwater flow, the water source and development of channels has been widely debated. Possible mechanisms include: (i) gradual formation by water flow in a subglacially deforming bed into channels under steady-state conditions; (ii) time-transgressive formation close to the ice margin by drainage of supraglacial meltwater to the bed or of meltwater temporarily impounded behind a permafrost wedge; and or (iii) by catastrophic subglacial meltwater floods. We have mapped and analysed the spatial pattern and morphometry of tunnel valleys and associated glacial bedforms along the southern sector of the former Laurentide Ice Sheet from high-resolution digital elevation models. Around 2000 tunnel valleys have been mapped, revealing a well-organised pattern of sub-parallel, semi-regularly spaced valleys that cluster together in distinctive networks. The tunnel valleys are typically <20 km long, and 0.5-3 km wide and preferentially terminate at moraines. They tend to be associated with outwash fans, eskers, glacial curvilineations, giant current ripples, and hill-hole-pairs. A relative age of the tunnel valleys, based on cross-cutting relationships, is used to resolve when individual tunnel valleys and networks were eroded. Our results suggest a time-transgressive origin for most tunnel valleys (i.e. they grow upstream) with some contributions from large meltwater drainage events.

  2. Geophysical Investigations of Structures within Southern Fish Lake Valley, California

    NASA Astrophysics Data System (ADS)

    McBride, K.; Ferguson, J. F.; Oldow, J. S.

    2015-12-01

    The 80km Fish Lake Valley Fault Zone makes up the northern portion of the Furnace Creek - Death Valley Fault Zone, a 250km right lateral oblique strike slip system that accounts for up to 25% of the relative motion between the Pacific and North American Plates. The Cucomongo Canyon Restraining bend lies to the south of Fish Lake Valley, and causes localized uplift. The developmental history of the Cucomongo Canyon restraining bend and the resultant uplift, deformation, and displacement is the focus of an integrated study by the Miles Geoscience Center at the University of Texas at Dallas. This specific part of the study focuses on the southernmost section of Fish Lake Valley, where Paleozoic sedimentary rocks are juxtaposed with Cenozoic sediments on multiple faulted boundaries. Structural constraints are not very well known as the faults are locally obscured by Quaternary alluvial deposits of various ages. Analysis of high resolution topography, produced from LiDAR scanning performed by the Miles team, and imagery shows subtle geomorphic expressions related to faulting. A near surface geophysical survey utilizing high resolution seismic refraction and microGal gravity measurements was done to explore the subsurface beneath the alluvium. Forward models were created to identify faults and ascertain vertical offsets and orientations. The geophysical models indicate a zone of extensional deformation north of the restraining bend

  3. Provenance, Offset Equivalent and Palinspastic Reconstruction of the Miocene Cajon Valley Formation, Southern California

    NASA Astrophysics Data System (ADS)

    Stang, Dallon Michael

    Petrographic, conglomerate and detrital-zircon analyses of formations in southern California can determine consanguineous petrofacies and lithofacies that help constrain paleotectonic and paleogeographic reconstructions of the southwestern United States. Arkosic sandstone of the lower Middle Miocene Cajon Valley formation is exposed on the southwest edge of the Mojave block and juxtaposed against Mesozoic and Paleozoic rocks by the San Andreas fault (SAf). Early work in Cajon Valley referred to the formation as Punchbowl, due to its similar appearance to the Punchbowl Formation at Devil's Punchbowl (northwest along the SAf). However, paleontological work placed Cajon Valley strata in the Hemingfordian-Barstovian (18-14 Ma), as opposed to the Clarendonian-Hemphillian (13-9 Ma) Punchbowl Formation. Since the Cajon Valley formation was deposited prior to being truncated by the San Andreas fault, the 2400m-thick, laterally extensive subaerial deposits likely were deposited across what is now the fault trace. Restoring 310 km of dextral slip on the SAf system should indicate the location of offset equivalent sandstone. Restoration of slip on the SAf system places Cajon Valley adjacent to the Caliente and La Panza Ranges, east of San Luis Obispo. Although analysis of detrital zircon from Cenozoic sandstone throughout southern California has been crucial in establishing paleodrainage areas, detrital zircon from the Cajon Valley and equivalent formations had not been analyzed prior to this study. Paleocurrents measured throughout the Cajon Valley formation indicate a source to the NE, in the Mojave Desert. Sandstone samples analyzed in thin section using the Gazzi-Dickinson method of point-counting are homogeneously arkosic, with slight compositional variability, making differentiation of the Cajon Valley formation and potential offset equivalents problematic. However, Branch Canyon Sandstone and Santa Margarita Formation samples are compositionally the best match for the

  4. Miocene rapakivi granites in the southern Death Valley region, California, USA

    USGS Publications Warehouse

    Calzia, J.P.; Ramo, O.T.

    2005-01-01

    Rapakivi granites in the southern Death Valley region, California, include the 12.4-Ma granite of Kingston Peak, the ca. 10.6-Ma Little Chief stock, and the 9.8-Ma Shoshone pluton. All of these granitic rocks are texturally zoned from a porphyritic rim facies, characterized by rapakivi textures and miarolitic cavities, to an equigranular aplite core. These granites crystallized from anhydrous and peraluminous to metaluminous magmas that were more oxidized and less alkalic than type rapakivi granites from southern Finland. Chemical and isotope (Nd-Sr-Pb) data suggest that rapakivi granites of the southern Death Valley region were derived by partial melting of lower crustal rocks (possibly including Mesozoic plutonic component) with some mantle input as well; they were emplaced at shallow crustal levels (4 km) in an actively extending orogen.

  5. Selected hydrologic data for southern Utah and Goshen Valleys, Utah, 1890-1992

    USGS Publications Warehouse

    Stolp, B.J.; Drumiler, M.J.; Brooks, L.E.

    1993-01-01

    This report contains hydrologic data collected in southern Utah and Goshen Valleys from 1890 to 1992. Southern Utah and Goshen Valleys are south of Salt Lake City in Utah County, north-central Utah. The area is bounded on the east and south by the Wasarch Range, on the south by Long Ridge, on the west by the East Tintic Mountains and the Mosida Hills, and on the north by a line through about the middle of T. 7 S. Southern Utah Valley and Goshen Valley are divided by the northern tip of Long Ridge, West Mountain, and Utah Lake. The area is in the Basin and Range physiographic province and includes about 390 square miles. Hydrologic data presented include records of over 400 wells. drillers' logs for selected wells, water-level data from wells, well discharge, and chemical analyses of water from about 90 wells. Discharge, water temperature, and specific conductance of water are given for about 15 selected springs and drains, and for streams and canals.

  6. Wrench model for east side of southern San Joaquin Valley

    SciTech Connect

    Nicholson, G.E.

    1986-04-01

    Compressional deformation is evident on the east side of the San Joaquin Valley; however, since normal faulting is the main trapping mechanism for east-side oil fields, the causes and effects of this compression have rarely been addressed. An investigation of surface lineaments and fault traces in the area, combined with various subsurface data, suggests that an east-west stress couple resulted in several structures that are typically associated with wrenching. To account for the geometry of these linears and for having reverse faulting and normal faulting in the same area, a wrench model has been developed, which indicates that many of these features are interrelated. Key components of the model are that right-lateral movement has occurred along the White Wolf fault and left-lateral movement has been interpreted along an antithetic lineament trending northwest from the mouth of Caliente Creek to the west end of Poso Creek (the Bakersfield lineament). The strain ellipsoid also accommodates observed folding and reverse faulting. Deformation was most intense during early late Miocene, probably before the Santa Margarita Formation was deposited. Subsequent deposits of predominantly nonmarine sediments tend to mask many Miocene structures. However, their presence is often reflected at the surface in the form of lineaments, drape folds, and faulting. Recent movement on the White Wolf fault in the 1952 Tehachapi earthquake indicates that compressional forces still exist in the area. Structural features described by the model contributed to trapping oil on the east side. The model ties together various structural data from a widespread area and may help predict the presence of other oil accumulations.

  7. Interpretation of magnetic surveys in intermontane valleys of Nevada and southern New Mexico

    USGS Publications Warehouse

    Bath, G.D.

    1976-01-01

    An evaluation of the magnetic method of geophysical exploration in intermontane valleys is made through examples of magnetic properties, magnetic surveys, reduction of data, and analysis of magnetic anomalies from some valley areas. Measurements of magnetic properties of samples collected along valley margins or from drill holes indicate that the anomaly-producing rocks are mostly Tertiary volcanic flows in Nevada and mostly Cretaceous-Tertiary intrusives in southern New Mexico. Aeromagnetic data were compiled as both observed and residual anomalies from surveys at various flight-line spacings and intervals from ground surface. Theoretical anomalies from known models were analyzed to recover data on depth, width, and magnetization of models and thereby establish reliability of methods used by certain investigators. These methods were then applied to measured anomalies to obtain information about the igneous rock structures that are buried beneath nonmagnetic valley alluvium. Recommendations made for future valley studies include aeromagnetic surveys flown 150 m above ground surface and at 800 m spacing; measurement of magnetic properties from outcrop samples, drill-core samples, and magnetometer logging of uncased drill holes; and use of the interpretation from gravity surveys in the same area.

  8. Principal facts for gravity stations in the Elko, Steptoe Valley, Coyote Spring Valley, and Sheep Range areas, eastern and southern Nevada

    USGS Publications Warehouse

    Berger, D.L.; Schaefer, D.H.; Frick, E.A.

    1990-01-01

    Principal facts for 537 gravity stations in the carbonate-rock province of eastern and southern Nevada are tabulated and presented. The gravity data were collected in support of groundwater studies in several valleys. The study areas include the Elko area, northern Steptoe Valley, Coyote Spring Valley, and the western Sheep Range area. The data for each site include values for latitude, longitude, altitude, observed gravity, free- air anomaly, terrain correction, and Bouguer anomaly (calculated at a bedrock density of 2.67 g/cu cm. (USGS)

  9. Shallow velocity structure in the Imperial Valley region of Southern California

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Stock, J. M.; Hole, J. A.; Fuis, G. S.

    2013-12-01

    The Imperial Valley, located south of the Salton Sea of Southern California, contains a pull-apart basin formed by the on-going oblique extension between the southernmost San Andreas fault and the northern Imperial fault. In this very seismically active area, the earthquakes tend to occur in the form of seismic swarms (e.g. events in August 2012), often related to the geothermal systems in the valley. Previous active seismic studies (e.g. Fuis et al. 1979, Parsons and McCarthy 1996) have revealed major crustal structures including the shallow basin structures in the valley and surroundings, based primarily on 2D models. A better 3D structure model is still awaiting construction to provide improved information on the location of earthquakes, faults, fault-zone properties, and the evolution of the basin. The 2011 Salton Seismic Imaging Project (SSIP) deployed a seismic array at 2-km grid spacing in the central northern part of the valley (Line 11), and three longer seismic lines across the valley with active sources (Lines 1, 2, and 3). Here we will present the shallow (to 8-km depth) 3D structure in this region obtained by modeling the traveltimes of the first arrivals in these recordings and from earlier experiments. We have processed arrivals from all shots at all receivers, from the SSIP dataset, in the region south of the Salton Sea. Relevant data from the 1979 Imperial Valley experiment has also been used. The 3D structure of the valley was inverted from the surface to 8-km depth using the technique of Hole (1992). On average, the velocity increases rapidly from ~2 km/s at the surface to 5.6 km/s at 5 km depth, a velocity range corresponding to the unmetamorphosed sediments (Fuis et al. 1984). Below 5-km depth, velocity increases slowly to 6.3 km/s at 8-km depth, a velocity range corresponding to the metasedimentary rocks, or 'basement' (Fuis et al. 1984). In depth slices, geothermal areas are characterized by high velocity zones. Specifically, we observe a

  10. Population genetic structure of Anopheles arabiensis and Anopheles gambiae in a malaria endemic region of southern Tanzania

    PubMed Central

    2011-01-01

    Background Genetic diversity is a key factor that enables adaptation and persistence of natural populations towards environmental conditions. It is influenced by the interaction of a natural population's dynamics and the environment it inhabits. Anopheles gambiae s.s. and Anopheles arabiensis are the two major and widespread malaria vectors in sub-Saharan Africa. Several studies have examined the ecology and population dynamics of these vectors. Ecological conditions along the Kilombero valley in Tanzania influence the distribution and population density of these two vector species. It remains unclear whether the ecological diversity within the Kilombero valley has affected the population structure of An. gambiae s.l. populations. The goal of this study was to characterise the genetic structure of sympatric An. gambiae s.s and An. arabiensis populations along the Kilombero valley. Methodology Mosquitoes were collected from seven locations in Tanzania: six from the Kilombero valley and one outside the valley (~700 km away) as an out-group. To archive a genome-wide coverage, 13 microsatellite markers from chromosomes X, 2 and 3 were used. Results High levels of genetic differentiation among An. arabiensis populations was observed, as opposed to An. gambiae s.s., which was genetically undifferentiated across the 6,650 km2 of the Kilombero valley landscape. It appears that genetic differentiation is not attributed to physical barriers or distance, but possibly by ecological diversification within the Kilombero valley. Genetic divergence among An. arabiensis populations (FST = 0.066) was higher than that of the well-known M and S forms of An. gambiae s. s. in West and Central Africa (FST = 0.035), suggesting that these populations are maintained by some level of reproductive isolation. Conclusion It was hypothesized that ecological diversification across the valley may be a driving force for observed An. arabiensis genetic divergence. The impact of the observed An

  11. Recurrent late Quaternary surface faulting along the southern Mohawk Valley fault zone, NE California

    SciTech Connect

    Sawyer, T.L.; Hemphill-Haley, M.A. ); Page, W.D. )

    1993-04-01

    The Mohawk Valley fault zone comprises NW- to NNW-striking, normal and strike-slip( ) faults that form the western edge of the Plumas province, a diffuse transitional zone between the Basin and Range and the northern Sierra Nevada. The authors detailed evaluation of the southern part of the fault zone reveals evidence for recurrent late Pleistocene to possibly Holocene, moderate to large surface-faulting events. The southern Mohawk fault zone is a complex, 6-km-wide zone of faults and related features that extends from near the crest of the Sierra Nevada to the middle of southern Sierra Valley. The fault zone has two distinct and generally parallel subzones, 3 km apart, that are delineated by markedly different geomorphic characteristics and apparently different styles of faulting. Paleoseismic activity of the western subzone was evaluated in two trenches: one across a fault antithetic to the main range-bounding fault, and the other across a splay fault delineated by a 3.7-m-high scarp in alluvium. Stratigraphic relations, soil development, and radiocarbon dates indicate that at least four mid- to late-Pleistocene surface-faulting events, having single-event displacements in excess of 1.6 to 2.6 m, occurred along the splay fault prior to 12 ka. The antithetic fault has evidence of three late Pleistocene events that may correspond to event documented on the splay fault, and a Holocene event that is inferred from youthful scarplets and small closed depressions.

  12. Biologically relevant physical measurements in the ice-free valleys of southern Victoria Land: soil temperature profiles and ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Nienow, J. A.; Meyer, M. A.; Friedmann, E. I. (Principal Investigator)

    1986-01-01

    As part of the ongoing comprehensive study of the cryptoendolithic microbial community in the ice-free valleys of southern Victoria Land, thermal properties of the soil and the ultraviolet radiation regime were measured. Although soil temperature profiles have been measured in the ice-free valleys (e.g., Cameron et al. 1970; Cameron 1972), these are the first such data from higher elevations. This is apparently the first time the ultraviolet radiation regime has been measured in the Antarctic.

  13. On the formation of the tunnel valleys of the southern Laurentide ice sheet

    USGS Publications Warehouse

    Hooke, R. LeB; Jennings, C.E.

    2006-01-01

    Catastrophic releases of meltwater, produced by basal melting and stored for decades in subglacial reservoirs at high pressure, may have been responsible for eroding the broad, deep tunnel valleys that are common along the margins of some lobes of the southern Laurentide ice sheet. We surmise that these releases began when the high water pressure was transmitted to the margin through the substrate. The water pressure in the substrate at the margin would then have been significantly above the overburden pressure, leading to sapping failure. Headward erosion of a conduit in the substrate (piping) could then tap the stored water, resulting in the outburst. In some situations, development of a siphon may have lowered the reservoir below its overflow level, thus tapping additional water. Following the flood, the seal could have reformed and the reservoir refilled, setting up conditions for another outburst. Order of magnitude calculations suggest that once emptied, a subglacial reservoir could refill in a matter of decades. The amount of water released during several outbursts appears to be sufficient to erode a tunnel valley. We think that tunnel valleys are most likely to have formed in this way where and when the glacier margin was frozen to the bed and permafrost extended from the glacier forefield several kilometers back under the glacier, as reservoirs would then have been larger and more common, and the seal more robust and more likely to reform after an outburst. ?? 2006 Elsevier Ltd. All rights reserved.

  14. Impact of valley fills on streamside salamanders in southern West Virginia

    USGS Publications Warehouse

    Wood, Petra Bohall; Williams, Jennifer M.

    2013-01-01

    Valley fills associated with mountaintop-removal mining bury stream headwaters and affect water quality and ecological function of reaches below fills. We quantified relative abundance of streamside salamanders in southern West Virginia during 2002 in three streams below valley fills (VFS) and in three reference streams (RS). We surveyed 36 10- × 2-m stream transects, once in summer and fall, paired by order and structure. Of 2,343 salamanders captured, 66.7% were from RS. Total salamanders (adults plus larvae) were more abundant in RS than VFS for first-order and second-order reaches. Adult salamanders had greater abundance in first-order reaches of RS than VFS. Larval salamanders were more abundant in second-order reaches of RS than VFS. No stream width or mesohabitat variables differed between VFS and RS. Only two cover variables differed. Silt cover, greater in VFS than RS first-order reaches, is a likely contributor to reduced abundance of salamanders in VFS. Second-order RS had more boulder cover than second-order VFS, which may have contributed to the higher total and larval salamander abundance in RS. Water chemistry assessments of our VFS and RS reported elevated levels of metal and ion concentrations in VFS, which can depress macroinvertebrate populations and likely affect salamander abundance. Valley fills appear to have significant negative effects on stream salamander abundance due to alterations in habitat structure, water quality and chemistry, and macroinvertebrate communities in streams below fills.

  15. On the formation of the tunnel valleys of the southern Laurentide ice sheet

    NASA Astrophysics Data System (ADS)

    Hooke, Roger LeB.; Jennings, Carrie E.

    2006-06-01

    Catastrophic releases of meltwater, produced by basal melting and stored for decades in subglacial reservoirs at high pressure, may have been responsible for eroding the broad, deep tunnel valleys that are common along the margins of some lobes of the southern Laurentide ice sheet. We surmise that these releases began when the high water pressure was transmitted to the margin through the substrate. The water pressure in the substrate at the margin would then have been significantly above the overburden pressure, leading to sapping failure. Headward erosion of a conduit in the substrate (piping) could then tap the stored water, resulting in the outburst. In some situations, development of a siphon may have lowered the reservoir below its overflow level, thus tapping additional water. Following the flood, the seal could have reformed and the reservoir refilled, setting up conditions for another outburst. Order of magnitude calculations suggest that once emptied, a subglacial reservoir could refill in a matter of decades. The amount of water released during several outbursts appears to be sufficient to erode a tunnel valley. We think that tunnel valleys are most likely to have formed in this way where and when the glacier margin was frozen to the bed and permafrost extended from the glacier forefield several kilometers back under the glacier, as reservoirs would then have been larger and more common, and the seal more robust and more likely to reform after an outburst.

  16. Late Cenozoic crustal extension and magmatism, southern Death Valley region, California

    USGS Publications Warehouse

    Calzia, J.P.; Rämö, O.T.

    2000-01-01

    The late Cenozoic geologic history of the southern Death Valley region is characterized by coeval crustal extension and magamatism. Crustal extension is accommodated by numerous listric and planar normal faults as well as right- and left-lateral strike slip faults. The normal faults sip 30°-50° near the surface and flatten and merge leozoic miogeoclinal rocks; the strike-slip faults act as tear faults between crustal blocks that have extended at different times and at different rates. Crustal extension began 13.4-13.1 Ma and migrated northwestward with time; undeformed basalt flows and lacustrine deposits suggest that extension stopped in this region (but continued north of the Death Valley graben) between 5 and 7 Ma. Estimates of crustal extension in this region vary from 30-50 percent to more than 100 percent. Magmatic rocks syntectonic with crustal extension in the southern Death Valley region include 12.4-6.4 Ma granitic rocks as well as bimodal 14.0-4.0 Ma volcanic rocks. Geochemical and isotopic evidence suggest that the granitic rocks get younger and less alkalic from south to north; the volcanic rocks become more mafic with less evidence of crustal interaction as they get younger. The close spatial and temporal relation between crustal extension and magmatism suggest a genetic and probably a dynamic relation between these geologic processes. We propose a rectonic-magmatic model that requires heat to be transported into the crust by mantle-derived mafic magmas. These magmas pond at lithologic or rheologic boundaries, begin the crystallize, and partially melt the surrounding crustal rocks. With time, the thermally weakened crust is extended (given a regional extensional stress field) concurrent with granitic magmatism and bimodal volcanism.

  17. Morphological properties of tunnel valleys of the southern sector of the Laurentide Ice Sheet and implications for their formation

    NASA Astrophysics Data System (ADS)

    Livingstone, Stephen J.; Clark, Chris D.

    2016-07-01

    Tunnel valleys have been widely reported on the bed of former ice sheets and are considered an important expression of subglacial meltwater drainage. Although known to have been cut by erosive meltwater flow, the water source and development of channels has been widely debated; ranging between outburst flood events through to gradually occurring channel propagation. We have mapped and analysed the spatial pattern and morphometry of tunnel valleys and associated glacial landforms along the southern sector of the former Laurentide Ice Sheet from high-resolution digital elevation models. Around 2000 tunnel valleys have been mapped, revealing an organised pattern of sub-parallel, semi-regularly spaced valleys that form in distinctive clusters. The tunnel valleys are typically < 20 km long, and 0.5-3 km wide, although their width varies considerably down-valley. They preferentially terminate at moraines, which suggests that formation is time dependent; while we also observe some tunnel valleys that have grown headwards out of hill-hole pairs. Analysis of cross-cutting relationships between tunnel valleys, moraines and outwash fans permits reconstruction of channel development in relation to the retreating ice margin. This palaeo-drainage reconstruction demonstrates incremental growth of most valleys, with some used repeatedly or for long periods, during deglaciation, while others were abandoned shortly after their formation. Our data and interpretation support gradual (rather than a single-event) formation of most tunnel valleys with secondary contributions from flood drainage of subglacial and or supraglacially stored water down individual tunnel valleys. The distribution and morphology of tunnel valleys is shown to be sensitive to regional factors such as basal thermal regime, ice and bed topography, timing and climate.

  18. Paleontologic investigations of the uppermost Santa Susana Formation, south side of Simi Valley, southern California

    SciTech Connect

    Squires, R.L. )

    1991-02-01

    Strata assignable to the provincial macroinvertebrate Meganos stage, equivalent to the calcareous nannofossil CP8 zone (late Paleocene) to CP9 zone (early Eocene), are uncommon on the Pacific coast of North America. This stage has been recognized in southern California only in the uppermost Santa Susana Formation, north side of Simi Valley. Although early workers reported meganos stage strata from the south side of Simi Valley, most of these deposits have since been assigned to younger or older stages. Intensive collecting by the author now proves that Meganos stage fossils are present in the upper 100 m of the Santa Susana Formation on the south side of the Simi Valley, east of the Runkle Canyon fault. This 100-m-thick interval consists of gray, very fine-grained sandstone that has a gradational lithology from the underlying gray mudstone. Calcareous nannofossils were found only near the bottom of the 100-m-thick interval, and they are suggestive of the late Paleocene Discoaster multiradiatus (CP8) zone. Rare, macrofossil-bearing lenses near the bottom of the 100-m-thick interval contain the solitary coral Trochocyathus zitteli, the gastropods Turritella subuvasana and the Velates californicus( ), and the bivalve Fimbria susanensis. Sparsely occurring, macrofossil-bearing lenses in the upper 20 m of the 100-m-thick- interval contain the colonial coral Archohelia clarki and the gastropod Turritella andersoni susanae (= T. andersoni n. subsp. of authors). Turritella andersoni susanae indicates the early Eocene part of the Meganoz stage because it is found just above the earliest Eocene Discoaster diastypus (CP9) zone in the upper Santa Susana Formation on the north side of Simi Valley.

  19. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historical episodic outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns (El Niño and La Niña) of El Niño Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite ...

  20. Prediction, Assessment of the Rift Valley fever Activity in East and Southern Africa 2006 - 2008 and Possible Vector Control Strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Nino/Southern Oscillation (ENSO) phenomenon which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and ...

  1. Yield, pollination aspects and kernel qualities of almond (Prunus amygdalus Batsch) selections trialed in the Southern San Joaquin Valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field trial was established in the Southern San Joaquin Valley to determine yield potential for nine almond selections grown under commercial conditions. Kernel yields were first quantified in 2008, at the end of the third growing season, and continued through the 2010 harvest. Harvested tonnage...

  2. Factors Motivating Latino College Students to Pursue STEM Degrees on CSU Campuses in the Southern San Joaquin Valley

    ERIC Educational Resources Information Center

    Ramirez, Gabriel

    2014-01-01

    The purpose of this study was to determine what factors were motivating Latino/a students in the southern San Joaquin Valley to pursue STEM degrees and whether these factors were specific to the Latino/a culture. A 12-question survey was administered to STEM majors at California State University, Bakersfield and California State University, Fresno…

  3. Impacts of changing irrigation practices on waterfowl habitat use in the southern San Joaquin Valley, California

    USGS Publications Warehouse

    Barnum, D.A.; Euliss, N. H .

    1991-01-01

    We used diurnal aerial census data to examine habitat use patterns of ducks wintering in the southern San Joaquin Valley, California from 1980-87. We calculated densities (birds/ha) for the northern pintail (Anas acuta), mallard (A. platyrhynchos), green-winged teal (A. crecca), cinnamon teal (A. cyanoptera), shoveler (A. clypeata), ruddy duck (Oxyura jamaicensis), and total ducks in each of 5 habitats. Densities of pintail and total ducks were greater in September than in other months. From October through January, density of teal and total ducks was greatest on Kern National Wildlife Refuge (NWR). Densities of ruddy duck and pintail were greatest on agricultural drainwater evaporation ponds and preirrigated cropland, respectively.

  4. Geochemical evidence for seasonal controls on the transportation of Holocene loess, Matanuska Valley, southern Alaska, USA

    NASA Astrophysics Data System (ADS)

    Muhs, Daniel R.; Budahn, James R.; Skipp, Gary L.; McGeehin, John P.

    2016-06-01

    Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to the east, which rules out the Susitna River as a source. Knik and Matanuska River silts can be distinguished using Sc-Th-La, LaN/YbN vs. Eu/Eu∗, Cr/Sc, and As/Sb. Matanuska Valley loess falls clearly within the range of values for these ratios found in Matanuska River silt. Dust storms from the Matanuska River are most common in autumn, when river discharge is at a minimum and silt-rich point bars are exposed, wind speed from the north is beginning to increase after a low-velocity period in summer, snow depth is still minimal, and soil temperatures are still above freezing. Thus, seasonal changes in climate and hydrology emerge as critical factors in the timing of aeolian silt transport in southern Alaska. These findings could be applicable to understanding seasonal controls on Pleistocene loess accretion in Europe, New Zealand, South America, and elsewhere in North America.

  5. Sedimentary petrology and tectonic significance of Tertiary sediments in southern White River Valley, Nevada

    SciTech Connect

    Diguiseppi, W.H.

    1987-08-01

    Up to 20 m of undated Tertiary sediment have been exposed by incision of the White River in southern White River Valley, Nevada. The sediments, deposited in two distinct environments and time periods, range from conglomerate to mudstone. Older sediments comprise alluvial-fan and lacustrine facies deposited in a closed basin. Alluvial-fan grain size and provenance patterns indicate centripetal transport into a topographic low located on the western margin of the valley. Very fine grained sandstone to mudstone basin-center deposits contain pennate diatoms and perhaps other microfossils. The basin-fill deposits are unconformably overlain by stream-terrace conglomerate. Such terraces are found along the White River as far south as Lake Mead and relate to the present southward external drainage. Multiple terrace levels, formed during incision, reflect base-level changes in the Colorado River System. The valley is bounded by normal faults, on the east by the White River fault and west by the Pahroc fault, in apparent contrast to the half-graben form of nearby basins. The alluvial-fan deposits are cut by the Pahroc fault but appear to postdate slip on the White River fault. Facies patterns in the basin fill thus indicate concentration of fine-grained sediment near the fault that was active during deposition. Terrace conglomerates indicate progradation of coarse clastics across the fine basinal deposits after activity on the bounding fault ceased. These relationships support the recent hypothesis that coarse clastic sedimentation in a basin may reflect post-tectonic rather than syntectonic deposition.

  6. Geochemical evidence for seasonal controls on the transportation of Holocene loess, Matanuska Valley, southern Alaska, USA

    USGS Publications Warehouse

    Muhs, Daniel; Budahn, James R.; Skipp, Gary L.; McGeehin, John

    2016-01-01

    Loess is a widespread Quaternary deposit in Alaska and loess accretion occurs today in some regions, such as the Matanuska Valley. The source of loess in the Matanuska Valley has been debated for more than seven decades, with the Knik River and the Matanuska River, both to the east, being the leading candidates and the Susitna River, to the west, as a less favorable source. We report here new stratigraphic, mineralogic, and geochemical data that test the competing hypotheses of these river sources. Loess thickness data are consistent with previous studies that show that a source or sources lay to the east, which rules out the Susitna River as a source. Knik and Matanuska River silts can be distinguished using Sc–Th–La, LaN/YbN vs. Eu/Eu∗, Cr/Sc, and As/Sb. Matanuska Valley loess falls clearly within the range of values for these ratios found in Matanuska River silt. Dust storms from the Matanuska River are most common in autumn, when river discharge is at a minimum and silt-rich point bars are exposed, wind speed from the north is beginning to increase after a low-velocity period in summer, snow depth is still minimal, and soil temperatures are still above freezing. Thus, seasonal changes in climate and hydrology emerge as critical factors in the timing of aeolian silt transport in southern Alaska. These findings could be applicable to understanding seasonal controls on Pleistocene loess accretion in Europe, New Zealand, South America, and elsewhere in North America.

  7. Latest Pleistocene and Holocene glacial events in the Colonia valley, Northern Patagonia Icefield, southern Chile

    USGS Publications Warehouse

    Nimick, David A.; Mcgrath, Daniel; Mahan, Shannon; Friesen, Beverly A.; Leidich, Jonathan

    2016-01-01

    The Northern Patagonia Icefield (NPI) is the primary glaciated terrain worldwide at its latitude (46.5–47.5°S), and constraining its glacial history provides unique information for reconstructing Southern Hemisphere paleoclimate. The Colonia Glacier is the largest outlet glacier draining the eastern NPI. Ages were determined using dendrochronology, lichenometry, radiocarbon, cosmogenic 10Be and optically stimulated luminescence. Dated moraines in the Colonia valley defined advances at 13.2 ± 0.95, 11.0 ± 0.47 and 4.96 ± 0.21 ka, with the last being the first constraint on the onset of Neoglaciation for the eastern NPI from a directly dated landform. Dating in the tributary Cachet valley, which contains an ice-dammed lake during periods of Colonia Glacier expansion, defined an advance at ca. 2.95 ± 0.21 ka, periods of advancement at 810 ± 49 cal a BP and 245 ± 13 cal a BP, and retreat during the intervening periods. Recent Colonia Glacier thinning, which began in the late 1800s, opened a lower-elevation outlet channel for Lago Cachet Dos in ca. 1960. Our data provide the most comprehensive set of Latest Pleistocene and Holocene ages for a single NPI outlet glacier and expand previously developed NPI glacial chronologies.

  8. Dog ownership, dog behaviour and transmission of Echinococcus spp. in the Alay Valley, southern Kyrgyzstan.

    PubMed

    Van Kesteren, Freya; Mastin, Alexander; Mytynova, Bermet; Ziadinov, Iskender; Boufana, Belgees; Torgerson, Paul R; Rogan, Michael T; Craig, Philip S

    2013-11-01

    Echinococcosis is a re-emerging zoonotic disease in Kyrgyzstan, and the incidence of human infection has increased substantially since the collapse of the Soviet Union in 1991. Domestic dogs are hosts of Echinococcus spp. and play an important role in the transmission of these parasites. The demography, ecology and behaviour of dogs are therefore relevant in studying Echinococcus spp. transmission. Dog demographics, roles of dogs, dog movements and faecal environmental contamination were assessed in four rural communities in the Alay Valley, southern Kyrgyzstan. Arecoline purge data revealed for the first time that E. granulosus, E. canadensis and E. multilocularis were present in domestic dogs in the Alay Valley. Surveys revealed that many households had dogs and that dogs played various roles in the communities, as pets, guard dogs or sheep dogs. Almost all dogs were free to roam, and GPS data revealed that many moved outside their communities, thus being able to scavenge offal and consume rodents. Faecal environmental contamination was high, presenting a significant infection risk to the local communities.

  9. Bioindicators from Mosquitofish (Gambusia affinis) Sampled from the Imperial Valley in Southern California

    USGS Publications Warehouse

    Jenkins, Jill A.; Draugelis-Dale, Rassa O.

    2006-01-01

    The Sonny Bono Salton Sea National Wildlife Refuge (SSNWR) is located 64 km north of the Mexican border at the southern end of the Salton Sea in California's Imperial Valley. Freshwater ponds and managed habitats at the SSNWR, Calipatria, Calif. are supplied with Colorado River water that carries compounds from upstream sources. Components include municipal and industrial discharges, agricultural drainage, and sewage plant inputs. Aquatic animals in these ecosystems are continuously exposed to multiple constituents, several of which have been demonstrated to be associated with hormonal disturbances. We investigated possible endocrine impacts to fish in the Imperial Valley, Calif., by addressing the null hypothesis that aquatic species in impacted sites did not exhibit evidence of endocrine disruption as compared with those from nonimpacted sites. The results presented are intended to provide managers with science-based information and interpretations about the condition of the animals in their ecosystems for the minimization of potential adverse effects to trust fish and wildlife resources and for the maximization of available water resources.

  10. Late-glacial and Holocene river development in the Teleorman Valley on the southern Romanian Plain

    NASA Astrophysics Data System (ADS)

    Howard, A. J.; Macklin, M. G.; Bailey, D. W.; Mills, S.; Andreescu, R.

    2004-03-01

    This paper reports on a radiocarbon-dated sequence of alluvial terraces from the Teleorman Valley in the southern Romanian Plain and represents the first Late-glacial and well-constrained Holocene alluvial sequence from the lower Danube Valley of southeast Europe. The two earliest and most extensive terraces (T1 and T2) are dissected by large, high-amplitude palaeochannels, which are dated to ca. 12 800 yr BP and are comparable to large meandering palaeochannels identified from other Late glacial contexts across northern and central Europe. The remaining sequence of alluvial deposits show changes in river activity and accelerated sedimentation around 4900-4800 yr BP, 4000-3800 yr BP, 3300-2800 yr BP, 1000 yr BP and within the past 200 yr. A phase of tributary stream alluvial fan deposition is dated to ca. 2400 yr BP. All these periods of alluvial sedimentation correlate well with episodes of climatic cooling, higher rainfall and enhanced river activity, both in terms of incision and greater lateral mobility as well as increased flood frequency and magnitude identified elsewhere in central, western and northern Europe. Human activity appears to have had little effect on this river environment and significant fine-grained sedimentation is not noted until ca. 2400 yr BP, approximately 5000 yr after the first neolithic farmers settled the area. Whether this record of river activity truly reflects the impact of prehistoric societies on this catchment will only be elucidated through further, ongoing detailed archaeological research. Copyright

  11. Ground water in the Eugene-Springfield area, southern Willamette Valley, Oregon

    USGS Publications Warehouse

    Frank, F.J.

    1973-01-01

    The cities of Eugene and Springfield and their outlying suburban and rural districts constitute an area of rapid population growth where progressively greater volumes of ground water are being required for irrigation and industrial and public supplies. The area is also one of diverse geologic and hydrologic conditions. As used in this report, the Eugene-Springfield area covers about 450 square miles and includes a part of the lower foothills of the Coast and Cascade Ranges and a strip of the main valley plain of the southern Willamette Valley. Volcanic and sedimentary rock units exposed in the foothills range in age from Eocene to Miocene. In the main valley plain the older units are overlain by Pleistocene and Holocene alluvial deposits. Marine-deposited sandstone, siltstone, shale, and mudstone of the older sedimentary units are fine grained and poorly permeable and yield water slowly to wells. The volcanic rocks, primarily of dacitic and andesitic composition, yield small quantities of water that are generally adequate only for domestic use. The alluvial deposits (sand and gravel) of the valley plain (central lowland) contain the most productive aquifers in the area and are considered to be the only ground-water reservoir for which large-scale development of ground-water supplies is feasible. Aquifers in the area are recharged principally by direct infiltration of precipitation. Most of the precipitation, which averages about 4C inches per year, occurs during late autumn and winter. Minimum recharge by infiltration of precipitation to the alluvial aquifers beneath the valley plain is estimated to be about 100,000 acre-feet. Ground water is discharged naturally from the central lowland by seepage and spring flow to small streams, by subsurface outflow to adjacent areas, and by evapotranspiration. Storage capacity of the central lowland in the Eugene-Springfield area is estimated to be about 2.1 million acre-feet in the zone 10-150 feet below land surface. The

  12. Paleoseismic investigations of the Paintbrush Canyon fault in southern Midway Valley, Yucca Mountain, Nevada: Preliminary results

    SciTech Connect

    Swan, F.H.; Wesling, J.R.; Thomas, A.P. )

    1993-04-01

    Trench mapping in southern Midway Valley provides evidence of multiple surface-faulting events on a western splay of the Paintbrush Canyon fault during the middle to late Pleistocene. The 6-m-wide fault zone exposed in the trench strikes N30-45E and dips steeply ([approximately]78[degree]) to the west, although some shears within the zone dip to the east. Tertiary volcanic bedrock is exposed only on the footwall block within the trench. Unconsolidated colluvial and eolian deposits are present in the hanging-wall block and above bedrock in the footwall block. These deposits tentatively are assigned, respectively, mid Pleistocene and late Pleistocene ages based on correlations with surficial map units in Midway Valley. Three to five displacement events are inferred based on faulted colluvial and eolian deposits, and scarp-derived colluvial wedges. Total cumulative dip-slip displacement of the oldest middle Pleistocene subunit is estimated to be about 170 to 270 cm. The dip-slip displacement associated with the youngest event is about 15 cm. The earlier displacements are estimated to have produced between 40 and 85 cm of dip-slip displacement per event. The most recent event occurred after deposition of late Pleistocene colluvium deposited against the fault scarp but before deposition of an overlying hillslope-derived colluvium of probable late pleistocene age. Based on the preliminary results of the authors study, the middle to late Quaternary rate of dip-slip displacement is approximately 0.01 m/kyr or less. Ongoing work, including soil-stratigraphic studies and numerical dating of deposits, should better constrain the timing and a rate of faulting along this western splay of the Paintbrush Canyon fault.

  13. Epidemiologic and Environmental Risk Factors of Rift Valley Fever in Southern Africa from 2008 to 2011

    PubMed Central

    Glancey, Margaret M.; Linthicum, Kenneth J.

    2015-01-01

    Abstract Background: Rift Valley fever (RVF) outbreaks have been associated with periods of widespread and above-normal rainfall over several months. Knowledge on the environmental factors influencing disease transmission dynamics has provided the basis for developing models to predict RVF outbreaks in Africa. From 2008 to 2011, South Africa experienced the worst wave of RVF outbreaks in almost 40 years. We investigated rainfall-associated environmental factors in southern Africa preceding these outbreaks. Methods: RVF epizootic records obtained from the World Animal Health Information Database (WAHID), documenting livestock species affected, location, and time, were analyzed. Environmental variables including rainfall and satellite-derived normalized difference vegetation index (NDVI) data were collected and assessed in outbreak regions to understand the underlying drivers of the outbreaks. Results: The predominant domestic vertebrate species affected in 2008 and 2009 were cattle, when outbreaks were concentrated in the eastern provinces of South Africa. In 2010 and 2011, outbreaks occurred in the interior and southern provinces affecting over 16,000 sheep. The highest number of cases occurred between January and April but epidemics occurred in different regions every year, moving from the northeast of South Africa toward the southwest with each progressing year. The outbreaks showed a pattern of increased rainfall preceding epizootics ranging from 9 to 152 days; however, NDVI and rainfall were less correlated with the start of the outbreaks than has been observed in eastern Africa. Conclusions: Analyses of the multiyear RVF outbreaks of 2008 to 2011 in South Africa indicated that rainfall, NDVI, and other environmental and geographical factors, such as land use, drainage, and topography, play a role in disease emergence. Current and future investigations into these factors will be able to contribute to improving spatial accuracy of models to map risk areas

  14. Gravity and magnetic data in the vicinity of Virgin Valley, southern Nevada

    USGS Publications Warehouse

    Morin, Robert L.

    2006-01-01

    This report contains 10 interpretive cross sections and an integrated text describing the geology of parts of the Colorado, White River, and Death Valley regional ground-water flow systems, Nevada, Utah, and Arizona. The primary purpose of the report is to provide geologic framework data for input into a numerical ground-water model. Therefore, the stratigraphic and structural summaries are written in a hydrogeologic context. The oldest rocks (basement) are Early Proterozoic metamorphic and intrusive crystalline rocks that are considered confining units because of their low permeability. Late Proterozoic to Lower Cambrian clastic units overlie the crystalline rocks and are also considered confining units within the regional flow systems. Above the clastic units are Middle Cambrian to Lower Permian carbonate rocks that are the primary aquifers in the flow systems. The Middle Cambrian to Lower Permian carbonate rocks are overlain by a sequence of mainly clastic rocks of late Paleozoic to Mesozoic age that are mostly considered confining units, but they may be permeable where faulted. Tertiary volcanic and plutonic rocks are exposed in the northern and southern parts of the study area. In the Clover and Delamar Mountains, these rocks are highly deformed by north- and northwest-striking normal and strike-slip faults that are probably important conduits in transmitting ground water from the basins in the northern Colorado and White River flow systems to basins in the southern part of the flow systems. The youngest rocks in the region are Tertiary to Quaternary basin-fill deposits. These rocks consist of middle to late Tertiary sediments consisting of limestone, conglomerate, sandstone, tuff, and gypsum, and younger Quaternary surficial units consisting of alluvium, colluvium, playa deposits, and eolian deposits. Basin-fill deposits are both aquifers and aquitards.

  15. Holocene loess deposition and soil formation as competing processes, Matanuska Valley, southern Alaska

    USGS Publications Warehouse

    Muhs, D.R.; McGeehin, J.P.; Beann, J.; Fisher, E.

    2004-01-01

    Although loess-paleosol sequences are among the most important records of Quaternary climate change and past dust deposition cycles, few modern examples of such sedimentation systems have been studied. Stratigraphic studies and 22 new accelerator mass spectrometry radiocarbon ages from the Matanuska Valley in southern Alaska show that loess deposition there began sometime after ???6500 14C yr B.P. and has continued to the present. The silts are produced through grinding by the Matanuska and Knik glaciers, deposited as outwash, entrained by strong winds, and redeposited as loess. Over a downwind distance of ???40 km, loess thickness, sand content, and sand-plus-coarse-silt content decrease, whereas fine-silt content increases. Loess deposition was episodic, as shown by the presence of paleosols, at distances >10 km from the outwash plain loess source. Stratigraphic complexity is at a maximum (i.e., the greatest number of loesses and paleosols) at intermediate (10-25 km) distances from the loess source. Surface soils increase in degree of development with distance downwind from the source, where sedimentation rates are lower. Proximal soils are Entisols or Inceptisols, whereas distal soils are Spodosols. Ratios of mobile CaO, K2O, and Fe2O3 to immobile TiO2 show decreases in surface horizons with distance from the source. Thus, as in China, where loess deposition also takes place today, eolian sedimentation and soil formation are competing processes. Study of loess and paleosols in southern Alaska shows that particle size can vary over short distances, loess deposition can be episodic over limited time intervals, and soils developed in stabilized loess can show considerable variability under the same vegetation. ?? 2004 University of Washington. All rights reserved.

  16. Strike-Slip displacement along the Furnace Creek Fault Zone, southern Basins and Ranges, Death Valley, California

    NASA Astrophysics Data System (ADS)

    Baucke, W.; Cemen, I.

    2007-12-01

    The southern Basins and Ranges contain several strike-slip fault zones in addition to predominant normal faults. One of the strike-slip faults is the Furnace Creek fault zone (FCFZ) which extends from the Amor¬gosa Valley in eastern California northwestward continuously about 200 km and termi¬nates in the Fish Lake Valley in Nevada. The fault zone is a part of the Eastern California Shear Zone. Although the right-lateral sense of strike-slip movement along the FCFZ is undisputed, the magnitude of displacement has been controversial since the 1970s. Recently, we have mapped conglomerates exposed in the Travertine point area of the Furnace Creek Wash of the Death Valley region. The conglomerates are composed of Paleozoic clasts from the following formations: Bonanza King, Nopah, Pogonip, Eureka Quartzite, Hidden Valley, and Ely Springs Dolomite. Our analysis of these breccias showed that they are made out of clasts of one composition and a matrix that was slightly different. This observation and our microscopic analysis suggest to us that these breccias were formed as fault breccias along the Furnace Creek fault zone. We have also mapped breccias in the Desolation Canyon on the southwestern side of the FCFZ where the Bonanza King Formation is brought into structural contact over the Ely Spring Dolomite and Eureka Quartzite suggesting the presence of a thrust fault. We correlate this thrust fault with a similar structural setting along the Clery Thrust of the southern Funeral Mountains on northeastern sides of the FCFZ where the Clery thrust brings the Cambrian Bonanza King Formation over the Eureka Quartzite and Ely Spring Dolomite in the southern Funeral Mountains. These observations suggest to us that the thrust fault in the Desolation Canyon area is the continuation of the Clery Thrust of the southern Funeral Mountains. If this interpretation is correct, the strike-slip displacement along the FCFZ is about 30 km.

  17. Bovine trypanosomosis and Glossina distribution in selected areas of southern part of Rift Valley, Ethiopia.

    PubMed

    Sheferaw, Desie; Birhanu, Belay; Asrade, Biruhtesfa; Abera, Mesele; Tusse, Turist; Fikadu, Amha; Denbarga, Yifat; Gona, Zemedkun; Regassa, Alemayehu; Moje, Nebyou; Kussito, Engida; Mekibib, Berhanu; Asefa, Teshome; Woldesenbet, Zerihun

    2016-02-01

    Cross-sectional study was conducted in 9 selected districts of the southern part the Rift Valley, Ethiopia to estimate the dry period prevalence of bovine trypanosomosis as well as assessment of Glossina species. From a total of 1838 cattle examined for trypanosomosis by buffy coat technique 133 (7.2%) were found infected by trypanosome species. From the total positive animals 66.9 and 33.1% of them accounted to Trypanosoma congolense and Trypanosoma vivax, respectively. Significantly higher prevalence (19.4%., P<0.05) was recorded at Arba-Mnch district. Black colored cattle were the most highly affected (χ(2)=79.35, P<0.05) animals. The overall average PCV value for parasitaemic and aparasitaemic animals was 22.2 (95% CI=21.6-22.7) and 27% (95% CI=26.8-27.2), respectively. The fly caught per trap per day was 1.4 for Glossina species and 2.8 for other biting flies. Two species of Glossina identified namely Glossina pallidipes and Glossina fuscipes.

  18. 1995 Integrated Monitoring Study: Fog measurements in the Southern San Joaquin Valley - preliminary results

    SciTech Connect

    Collett, J. Jr.; Bator, A.; Sherman, D.E.

    1996-12-31

    Fogs were sampled at three ground-based stations in the southern portion of California`s San Joaquin Valley as part of the winter component of the 1995 Integrated Monitoring Study (IMS95). The three sampling sites included two urban locations (Bakersfield and Fresno) and one rural location (near the Kern Wildlife Refuge). Both bulk and drop size-fractionated samples were collected at each site. Several fog events were sampled, with three periods of extensive fog coverage that included all three sampling sites. Results of preliminary data analysis are presented. Fog collected at the sites was generally quite basic. Most bulk fog samples had pH values above 6 reflecting strong inputs from ammonia. Occasional strong sulfur plumes at Bakersfield, however, tended to lower the fog pH. Aside from these periods, nitrate was generally present at much higher concentrations in the fog than sulfate. Decreases in fogwater loadings of major species over the course of one extended fog episode at Fresno suggest significant deposition was occurring to the surface, consistent with observations of substantial droplet fluxes to exposed surfaces during that period. 16 refs., 7 figs., 1 tab.

  19. Decoupled extensional faulting and forced folding in the southern part of the Roer Valley Graben, Belgium

    NASA Astrophysics Data System (ADS)

    Deckers, Jef

    2015-12-01

    During late Oligocene incipient rifting, the southern part of the Roer Valley Graben was characterized by normal faulting and forced folding of its Paleogene pre-rift strata. The 2D seismic data used in this study shows that these faults and forced folds were geometrically decoupled from faults or fault zones in the underlying Triassic and older strata. Geometric decoupling consistently took place in an interval that comprises (latest Triassic to Early Jurassic) soft claystones on top of (Triassic) alternations of evaporites and claystones layers. This mechanically weak interval probably inhibited the upward propagation of (re)activated underlying faults, resulting in the formation of the observed forced folds (monoclines) in the overlying Paleogene pre-rift strata. Strain from the sub-detachment faults was distributed along the mechanically weak interval towards detachment edges, leading to the consistent presence of faults in the footwall domain of the supra-detachment monoclines. The mechanically weak interval was thereby able to maintain the kinematic coherency between geometrically decoupled under- and overlying deformation throughout late Oligocene rifting.

  20. Geological and geophysical characterization of the southeastern side of the High Agri Valley (southern Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Giocoli, A.; Stabile, T. A.; Adurno, I.; Perrone, A.; Gallipoli, M. R.; Gueguen, E.; Norelli, E.; Piscitelli, S.

    2015-02-01

    In the frame of a national project funded by Eni S.p.A. and developed by three institutes of the National Research Council (the Institute of Methodologies for Environmental Analysis, the Institute of Research for Hydrogeological Protection and the Institute for Electromagnetic Sensing of the Environment), a multidisciplinary approach based on the integration of satellite, aero-photogrammetric and in situ geophysical techniques was applied to investigate an area located in the Montemurro territory in the southeastern sector of the High Agri Valley (Basilicata Region, southern Italy). This paper reports the results obtained by the joint analysis of in situ geophysical surveys, aerial photos interpretation, morphotectonic investigation, geological field survey and borehole data. The joint analysis of different data allowed us (1) to show the shallow geological and structural setting, (2) to detect the geometry of the different lithological units and their mechanical and dynamical properties, (3) to image a previously unmapped fault beneath suspected scarps/warps and (4) to characterize the geometry of an active landslide affecting the study area.

  1. Fertilisation of the Southern Atlantic: Ephemeral River Valleys as a replenishing source of nutrient-enriched mineral aerosols

    NASA Astrophysics Data System (ADS)

    Dansie, Andrew; Wiggs, Giles; Thomas, David

    2016-04-01

    Oceanic dust deposition provides biologically important iron and macronutrients (Phosphorus (P) and Nitrogen-based (N) compounds) that contribute to phytoplankton growth, marine productivity and oceanic atmospheric CO2 uptake. Research on dust emission sources to date has largely focused on the northern hemisphere and on ephemeral lakes and pans. Our work considers the ephemeral river valleys of the west coast of Namibia as an important yet overlooked source of ocean-fertilizing dust. Dust plumes are frequently emitted from the river valleys by strong easterly winds during the Southern Hemisphere winter, when the upwelling of the Benguela Current is at its weakest. We present field data from dust emission source areas along the main river channels near the coastal termini of the Huab, Kuiseb and Tsauchab river valleys. Collected data include erodible surface sediment, wind-blown flux, and associated meteorological data. Extensive surface sediment sampling was also undertaken throughout the combined 34,250 km2 extent of each river valley catchment with samples collected from within the main river channels, the main branches of each river system, selected tributaries, and into the upper watersheds. Geochemical data show valley sediment and wind-blown flux material have high concentrations of bioavailable Fe, P and N, exceeding that measured at the major dry lake basin dust sources in southern Africa. The contribution of fertilising deposition material is enhanced by both the spatial proximity of the source areas to the ocean and enrichment of source material by ephemeral fluvial accumulation and desiccation. Results show that geographical factors within each watershed play a key role in the nutrient composition of the emitting fluvial deposits in the river valleys. Analysis explores potential relationships between land use, geology, climate and precipitation in the upper watersheds and their influence on bioavailability of Fe, P and N compounds in wind

  2. Orographic enhancement of rainfalls in the Rio San Francisco valley in southern Ecuador

    NASA Astrophysics Data System (ADS)

    Trachte, K.; Rollenbeck, R.; Bendix, J.

    2012-04-01

    In a tropical mountain rain forest in southern Ecuador diurnal dynamics of cloud development and precipitation behavior is investigated in the framework of the DFG research unit 816. With automatic climate stations and rain radar rainfalls in the Rio San Francisco valley are recorded. The observations showed the typical tropical late afternoon convective precipitation as well as local events such as mountain valley breezes and luv-lee effects. Additionally, the data revealed an unusually early morning peak that could be recognized as convective rainfalls. On the basis of GOES-E satellite imagery these rainfalls could be traced back to nocturnal convective clouds at the eastern Andes Mountains. There are some explanations for the occurrence of the clouds: One already examined mechanism is a katabatic induced cold front at the foothills of the Andes in the Peruvian Amazon basin. In this region the mountains form a quasi-concave configuration that contributes to a convergence of cold air drainage with subsequent convective activities. Another explanation for the events is the orographic enhancement by a local seeder-feeder mechanism. Mesoscale convective systems from the Amazon basin are transported to the west via the trade winds. At the Andes Mountains the complex and massive orography acts like a barrier to the clouds. The result is a disconnection of the upper part of the cloud from the lower part. The latter rains out at the eastern slopes and the upper cloud is transported further to the west. There it acts like a seeder to lower level clouds, i. e. the feeder. With the numerical model ARPS (Advanced Regional Prediction System) this procedure is investigated on the basis of two case studies. The events are detected and selected through the analysis of GOES-E brightness temperatures. They are also used to compare and validate the results of the model. Finally, the orographic enhancement of the clouds is examined. By using a vertically pointing radar the

  3. Eliminating Rabies in Tanzania? Local Understandings and Responses to Mass Dog Vaccination in Kilombero and Ulanga Districts

    PubMed Central

    Bardosh, Kevin; Sambo, Maganga; Sikana, Lwitiko; Hampson, Katie; Welburn, Susan C.

    2014-01-01

    Background With increased global attention to neglected diseases, there has been a resurgence of interest in eliminating rabies from developing countries through mass dog vaccination. Tanzania recently embarked on an ambitious programme to repeatedly vaccinate dogs in 28 districts. To understand community perceptions and responses to this programme, we conducted an anthropological study exploring the relationships between dogs, society, geography and project implementation in the districts of Kilombero and Ulanga, Southern Tanzania. Methodology/Principal Findings Over three months in 2012, we combined the use of focus groups, semi-structured interviews, a household questionnaire and a population-based survey. Willingness to participate in vaccination was mediated by fear of rabies, high medical treatment costs and the threat of dog culling, as well as broader notions of social responsibility. However, differences between town, rural and (agro-) pastoralist populations in livelihood patterns and dog ownership impacted coverage in ways that were not well incorporated into project planning. Coverage in six selected villages was estimated at 25%, well below official estimates. A variety of problems with campaign mobilisation, timing, the location of central points, equipment and staff, and project organisation created barriers to community compliance. Resource-limitations and institutional norms limited the ability for district staff to adapt implementation strategies. Conclusions and Significance In the shadows of resource and institutional limitations in the veterinary sector in Africa, top-down interventions for neglected zoonotic diseases likes rabies need to more explicitly engage with project organisation, capacity and community participation. Greater attention to navigating local realities in planning and implementation is essential to ensuring that rabies, and other neglected diseases, are controlled sustainably. PMID:24945697

  4. Striving for sustainable wildlife management: the case of Kilombero Game Controlled Area, Tanzania.

    PubMed

    Haule, K S; Johnsen, F H; Maganga, S L S

    2002-09-01

    The sustainability of wildlife resources in Africa is threatened by poaching for trophies and meat as well as changes in land use. In order to motivate local people for sustainable wildlife management, efforts to transfer decision-making power as well as benefits from central to local level have been made in several countries. Such efforts have not yet been seen in Kilombero Game Controlled Area, which is the area covered by the present study. The paper documents the importance of wildlife to local people, explores local people's perceptions on wildlife management and identifies constraints to sustainable wildlife management. A total of 177 household interviews in 5 villages and 129 interviews of pupils in schools have been conducted. The majority of pupils reported that their latest meal of meat was from a wild animal, and the most common species was buffalo. Apart from availability of cheap wildlife meat, advantages from living close to wildlife include the use of various parts of animals for, e.g. medical and ritual uses, and various plant products from wildlife habitats. Disadvantages include damages to crops, predation on livestock, and injuries to humans. The estimated loss of yield due to raiding by wildlife amounted to 21.9 and 47.8% of the harvest of rice and maize, respectively. Traditional wildlife management in Kilombero includes few rules to avoid resource depletion, because depletion has traditionally not been a problem due to low hunting technology and low human population. Government management includes strict rules, with hunting quotas as the main instrument, but the government has failed to enforce the rules. Ongoing discussions on new approaches to wildlife management like co-management and community-based management were largely unknown to the villagers in the area. Both poaching and agricultural expansion threaten the sustainability of Kilombero Game Controlled Area. It is suggested that transfers of decision-making power and benefits to local

  5. UAV's for active tectonics : case example from the Longitudinal Valley and the Chishan Faults (Southern Taiwan)

    NASA Astrophysics Data System (ADS)

    Deffontaines, Benoit; Chang, Kuo-Jen; Chan, Yu-Chang; Chen, Rou-Fei; Hsieh, Yu-Chung

    2015-04-01

    Taiwan is a case example to study active tectonics due to the active NW-SE collision of the Philippine and Eurasian Sea Plates as the whole convergence reaches 10cm/y. In order to decipher the structural active tectonics geometry, we used herein UAV's to get high resolution Digital Terrain Model (DTM) in local active tectonics key areas. Classical photo-interpretation where then developped in order to structurally interprete these data, confirmed by field studies. Two location had first been choosen in order to highlight the contribution of such high resolution DTM in SW Taiwan on the Longitudinal Valley Fault (SE Taiwan) on its southern branch from Pinting to Luyeh terraces (Pinanshan) where UAV's lead to better interprete the location of the outcropping active deformations. Combined with available GPS data and PALSAR interferometry (Deffontaines et Champenois et al., submitted) it is then possible to reconstruct the way of the present deformation in this local area. In the Pinting terraces, If the western branch of the fault correspond to an outcroping thrust fault, the eastern branch act as a a growing active anticline that may be characterized and quantified independantly. The interpretation of the UAV's high resolution DTM data on the Chishan Fault (SW Taiwan) reveals also the geometry of the outcropping active faults complex structural behaviour. If the Chishan Fault act as a thrusting in its northern tip (close to Chishan city), it acts as a right lateral strike-slip fault north of Chaoshan (Kaohsiung city) as described by Deffontaines et al. 2014. Therefore UAV's are a so useful tool to get very high resolution topographic data in Taiwan that are of great help to get the geometry of the active neotectonic structures in Taiwan.

  6. Late Glacial and Holocene Record of Hydroclimate in the San Luis Valley, Southern Colorado, USA

    NASA Astrophysics Data System (ADS)

    Yuan, F.; Koran, M.

    2012-12-01

    Lake sediments from the San Luis Valley, south-central Colorado, archive a detailed record of Late Glacial and Holocene climatic fluctuations in the southern Rocky Mountains. Together with radiometric dating analysis, measurements of grain size, magnetic susceptibility, total inorganic carbon (TIC), oxygen and carbon isotopic composition of the TIC fraction on sediment samples from San Luis Lake (at an average resolution of 60 years per sample) allow us to generate a sediment record of climatic change in the region spanning the last 16ka (1 ka=1000 cal yrs). This record documents the timing and duration of major climate episodes and trends, comparable to the existing paleoclimate records from the American Southwest. The Late Glacial record of San Luis Lake contains a big wet episode in the late part of the Mystery Interval (MI), a relatively dry climate during Bølling-Allerød (B/A) warm interval, and a relatively wet episode during the Younger Dryas (YD) interval, similar to the lake-level record found in the Estancia basin in central New Mexico. The early to middle Holocene record of d18O in the San Luis Lake parallels the calcite d18O record of Bison Lake in northern Colorado, documenting a history of significant change in precipitation seasonality across the northern boundary of the North American monsoon (NAM). The middle Holocene epoch is characterized by greater variations in magnetic susceptibility, d18O and d13C, suggesting the prevalence of wet, variable or transitional climate conditions. In contrast, the late Holocene climate is relatively dry, as indicated by more positive values of d18O in San Luis Lake. The results of this study reveal a complex history of climate evolution due to the interactions of two seasonally distinct precipitation regimes with mountainous landforms in the region.

  7. Characterization of intrabasin faulting and deformation for earthquake hazards in southern Utah Valley, Utah, from high-resolution seismic imaging

    USGS Publications Warehouse

    Stephenson, William J.; Odum, Jack K.; Williams, Robert A.; McBride, John H.; Tomlinson, Iris

    2012-01-01

    We conducted active and passive seismic imaging investigations along a 5.6-km-long, east–west transect ending at the mapped trace of the Wasatch fault in southern Utah Valley. Using two-dimensional (2D) P-wave seismic reflection data, we imaged basin deformation and faulting to a depth of 1.4 km and developed a detailed interval velocity model for prestack depth migration and 2D ground-motion simulations. Passive-source microtremor data acquired at two sites along the seismic reflection transect resolve S-wave velocities of approximately 200 m/s at the surface to about 900 m/s at 160 m depth and confirm a substantial thickening of low-velocity material westward into the valley. From the P-wave reflection profile, we interpret shallow (100–600 m) bedrock deformation extending from the surface trace of the Wasatch fault to roughly 1.5 km west into the valley. The bedrock deformation is caused by multiple interpreted fault splays displacing fault blocks downward to the west of the range front. Further west in the valley, the P-wave data reveal subhorizontal horizons from approximately 90 to 900 m depth that vary in thickness and whose dip increases with depth eastward toward the Wasatch fault. Another inferred fault about 4 km west of the mapped Wasatch fault displaces horizons within the valley to as shallow as 100 m depth. The overall deformational pattern imaged in our data is consistent with the Wasatch fault migrating eastward through time and with the abandonment of earlier synextensional faults, as part of the evolution of an inferred 20-km-wide half-graben structure within Utah Valley. Finite-difference 2D modeling suggests the imaged subsurface basin geometry can cause fourfold variation in peak ground velocity over distances of 300 m.

  8. Regional variations in water quality and relationships to soil and bedrock weathering in the southern Sacramento Valley, California, USA

    USGS Publications Warehouse

    Wanty, R.B.; Goldhaber, M.B.; Morrison, J.M.; Lee, L.

    2009-01-01

    Regional patterns in ground- and surface-water chemistry of the southern Sacramento Valley in California were evaluated using publicly available geochemical data from the US Geological Survey's National Water Information System (NWIS). Within the boundaries of the study area, more than 2300 ground-water analyses and more than 20,000 surface-water analyses were available. Ground-waters from the west side of the Sacramento Valley contain greater concentrations of Na, Ca, Mg, B, Cl and SO4, while the east-side ground-waters contain greater concentrations of silica and K. These differences result from variations in surface-water chemistry as well as from chemical reactions between water and aquifer materials. Sediments that fill the Sacramento Valley were derived from highlands to the west (the Coast Ranges) and east (the Sierra Nevada Mountains), the former having an oceanic provenance and the latter continental. These geologic differences are at least in part responsible for the observed patterns in ground-water chemistry. Thermal springs that are common along the west side of the Sacramento Valley appear to have an effect on surface-water chemistry, which in turn may affect the ground-water chemistry.

  9. Warming and glacier recession in the Rakaia valley, Southern Alps of New Zealand, during Heinrich Stadial 1

    SciTech Connect

    Aaron E. Putnam; Joerg M. Schaefe; George H .Denton; DavidJ. A. Barrell; Bjørn G. Andersen; Tobias N.B. Koffman; Ann V. Rowan; Robert C. Finkel; Dylan H. Rood; Roseanne Schwartz; Marcus J. Vandergoes; Mitchell A. Plummer; Simon H. Brocklehurst; Samuel E. Kelley; Kathryn L. Ladig

    2013-11-01

    The termination of the last ice age featured a major reconfiguration of Earth's climate and cryosphere, yet the underlying causes of these massive changes continue to be debated. Documenting the spatial and temporal variations of atmospheric temperature during deglaciation can help discriminate among potential drivers. Here, we present a 10Be surface-exposure chronology and glaciological reconstruction of ice recession following the Last Glacial Maximum (LGM) in the Rakaia valley, Southern Alps of New Zealand. Innermost LGM moraines at Big Ben have an age of 17,840 +/- 240 yrs, whereas ice-marginal moraines or ice-molded bedrock surfaces at distances up-valley from Big Ben of 12.5 km (Lake Coleridge), approximately 25 km (Castle Hill), approximately 28 km (Double Hill), approximately 43 km (Prospect Hill), and approximately 58 km (Reischek knob) have ages of 17,020 +/- 70 yrs, 17,100 +/- 110 yrs, 16,960 +/- 370 yrs, 16,250 +/- 340 yrs, and 15,660 +/- 160 yrs, respectively. These results indicate extensive recession of the Rakaia glacier, which we attribute primarily to the effects of climatic warming. In conjunction with geomorphological maps and a glaciological reconstruction for the Rakaia valley, we use our chronology to infer timing and magnitude of past atmospheric temperature changes. Compared to an overall temperature rise of approximately 4.65?degrees C between the end of the LGM and the start of the Holocene, the glacier recession between approximately 17,840 and approximately 15,660 yrs ago is attributable to a net temperature increase of approximately 4.0?degrees C (from -6.25 to -2.25?degrees C), accounting for approximately 86% of the overall warming. Approximately 3.75?degrees C (approximately 70%) of the warming occurred between approximately 17,840 and approximately 16,250 yrs ago, with a further 0.75?degrees C (approximately 16%) increase between approximately 16,250 and approximately 15,660 yrs ago. A sustained southward shift of the Subtropical

  10. Magnetotelluric evidence for crustal suture zones bounding the southern Great Valley, California

    SciTech Connect

    Park, S.K.; Biasi, G.P. ); Mackie, R.L.; Madden T.R. )

    1991-01-10

    A geoelectric section inferred from a regional magnetotelluric study across the Coast Ranges, the Great Valley, and the Sierra Nevada reveals significant variations in electrical resistivity. Zones of lower resistivity interpreted at depths from 10 km to at least 30 km lie near mapped geologic boundaries between the Coast Ranges and the Great Valley and beneath the eastern side of the Great Valley. The former boundary is inferred by others to separate the subduction complex of the Coast Ranges from the mafic basement of the Great Valley. The lower resistivities are most likely associated with metasediments trapped between the Coast Ranges ophiolite and the former oceanic crust beneath the Great Valley. The latter boundary is problematic, but may be evidence for a deep metasedimentary section trapped between the ophiolites beneath the Great Valley and granitic rocks of the Sierra Nevada. The lack of change in the magnetotelluric phase across the Great Valley indicates that a suture zone marked by lower resistivities is unlikely to be present beneath the valley. However, this does not preclude the existence of a resistive suture zone.

  11. Fluid injection induced seismicity reveals a NE dipping fault in the southeastern sector of the High Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Stabile, T. A.; Giocoli, A.; Perrone, A.; Piscitelli, S.; Lapenna, V.

    2014-08-01

    On 2 June 2006 the wastewater produced during the oil and gas field exploitation in High Agri Valley (southern Italy) started to be managed by disposal through pumping the fluids back into the subsurface at the Costa Molina 2 (CM2) injection well, located in the southeastern sector of the valley. The onset of microearthquakes (Ml ≤ 2) after 4 days at about 1.3 km SW of CM2 well suggests fluid injection induced seismicity by the diffusion of pore pressure. Moreover, the space-time evolution of 196 high-resolution relocated events reveals a previously unmapped NE dipping fault. We investigate the physical processes related to the fluid injection induced seismicity and delineate the previously unmapped fault by jointly analyzing seismicity data, geological observations, fluid injection data, the stratigraphic log of the CM2 well, and the electrical resistivity tomography survey carried out in the study area.

  12. Geochemistry of Mesozoic plutons, southern Death Valley region, California: Insights into the origin of Cordilleran interior magmatism

    USGS Publications Warehouse

    Ramo, O.T.; Calzia, J.P.; Kosunen, P.J.

    2002-01-01

    Mesozoic granitoid plutons in the southern Death Valley region of southeastern California reveal substantial compositional and isotopic diversity for Mesozoic magmatism in the southwestern US Cordillera. Jurassic plutons of the region are mainly calc-alkaline mafic granodiorites with ??Ndi of -5 to -16, 87Sr/86Sri of 0.707-0.726, and 206Pb/204Pbi of 17.5-20.0. Cretaceous granitoids of the region are mainly monzogranites with ??Ndi of -6 to -19, 87Sr/86Sri of 0.707-0.723, and 206Pb/204Pbi of 17.4-18.6. The granitoids were generated by mixing of mantle-derived mafic melts and pre-existing crust - some of the Cretaceous plutons represent melting of Paleoproterozoic crust that, in the southern Death Valley region, is exceptionally heterogeneous. A Cretaceous gabbro on the southern flank of the region has an unuasually juvenile composition (??Ndi -3.2, 87Sr/86Sri 0.7060). Geographic position of the Mesozoic plutons and comparison with Cordillera plutonism in the Mojave Desert show that the Precambrian lithosphere (craton margin) in the eastern Mojave Desert region may consists of two crustal blocks separated by a more juvenile terrane.

  13. Chronology and provenance of alluvial fills in the dry valley environment of the lower Molopo River, southern Kalahari

    NASA Astrophysics Data System (ADS)

    Ramisch, Arne; Bens, Oliver; Eden, Marie; Hürkamp, Kerstin; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    The dry valleys of the Molopo-Kuruman and the Nossob-Auob system form the largest drainage basin of the southern Kalahari, with a total drainage area of over 100.000 km². The South-Kalahari drainage system is connected to the perennial Orange River by the lower Molopo valley which is therefore the only potential fluvial outlet for sediments originating from the southern Kalahari. Despite its key geomorphological position, little is known about Late Quaternary landscape dynamic in the lower Molopo section. To estimate the timing of fluvial sedimentation phases near the Molopo-Orange confluence, we sampled alluvial fills within the narrow trench of the Molopo canyon. The chronology was established using a total of 15 Optical Stimulated Luminescence (OSL) samples from key profiles within the canyon. The results suggest that landscape development was dominated by two phases of valley infill during a) the Mid Holocene and b) the Late Holocene. To gain insight into sediment dynamics during these intervals, we carried out a provenance analysis on the fine fraction (< 2 mm) of fluvial sediments. Sediment source areas were estimated by analyzing the elemental and mineralogical composition of 93 tributaries and 32 dune deposits throughout the reaches of the lower Molopo via X-ray fluorescence (XRF) and X-ray diffraction analysis (XRD). The appliance of a fuzzy cluster algorithm on the elemental and mineralogical composition of reference samples revealed three major sediment source areas: i) The Molopo canyon, ii) fluvial source areas north of the canyon and iii) eolian sands covering the recent lower Molopo valley in its upper reaches. A similarity analysis between fluvial sediments of the Molopo canyon to the previously identified source areas suggests that alluvial fills mainly originate from the canyon itself, suggesting short-distance sediment mobilization as the driving mechanism behind aggradation. Thereby, both Holocene intervals differ in the mean distance of

  14. Exploring impacts of El Niño Southern Oscillation on Meteorological Forcing within the Glaciated Llanganuco Valley, Peru

    NASA Astrophysics Data System (ADS)

    Covert, J. M.; Hellstrom, R. A.

    2015-12-01

    El Niño Southern Oscillation (ENSO) is known to be the primary modulator of inter-annual weather patterns in the Andes, but its impact in the Cordillera Blanca (White Range) is not fully understood. In 2004 an autonomous sensor network (ASN) was installed in the Llanganuco Valley in the Cordillera Blanca, Peru consisting of two automatic weather stations (AWS) located at the base and upper ridge of the valley connected by four air temperature/humidity micro-loggers at equal elevation intervals. The ASN permits high resolution evaluations of the micro-scale meteorology within the valley. Twenty-four hour composites and monthly averages of wind, solar insolation, air temperature profiles, and precipitation obtained from the ASN were analyzed for the historical wet and dry seasons between the years of 2005 and 2015. The evidence suggests that teleconnections exist between eastern equatorial Pacific Ocean sea surface temperatures and meteorological forcing within the Valley. Comparisons between the two AWS units reveal similar ENSO impacts during the wet season that are not replicated in the dry season. We found that warm and cold ENSO create anomalies that appear unique to this region of the outer Tropics. Warm ENSO phases promote wetter than normal dry seasons and dryer than normal wet seasons and visa versa for cold phases of ENSO. Air temperature is strongly positively correlated to warm ENSO phases during the wet season and depends on elevation during the dry season. Insolation is negatively correlated to warm ENSO phases at higher elevations with weak positive correlation at lower elevations. We attribute observed seasonality, in part, to interactions between channeling of synoptic flow and thermally driven winds. Although the sporadic availability of data prevents definitive conclusions at this time, recent improvements in the ASN infrastructure will facilitate deeper understanding of ENSO impacts on meteorological forcing within pro-glacial valleys of the

  15. Stratigraphical framework of basaltic lavas in Torres Syncline main valley, southern Parana-Etendeka Volcanic Province

    NASA Astrophysics Data System (ADS)

    Rossetti, Lucas M.; Lima, Evandro F.; Waichel, Breno L.; Scherer, Claiton M.; Barreto, Carla J.

    2014-12-01

    The Paraná-Etendeka Volcanic Province records the volcanism of the Early Cretaceous that precedes the fragmentation of the South-Gondwana supercontinent. Traditionally, investigations of these rocks prioritized the acquisition of geochemical and isotopic data, considering the volcanic stack as a monotonous succession of tabular flows. Torres Syncline is a tectonic structure located in southern Brazil and where the Parana-Etendeka basalts are well preserved. This work provides a detailed analysis of lithofacies and facies architecture, integrated to petrographic and geochemical data. We identified seven distinct lithofacies grouped into four facies associations related to different flow morphologies. The basaltic lava flows in the area can be divided into two contrasting units: Unit I - pahoehoe flow fields; and Unit II - simple rubbly flows. The first unit is build up by innumerous pahoehoe lava flows that cover the sandstones of Botucatu Formation. These flows occur as sheet pahoehoe, compound pahoehoe, and ponded lavas morphologies. Compound lavas are olivine-phyric basalts with intergranular pyroxenes. In ponded lavas and cores of sheet flows coarse plagioclase-phyric basalts are common. The first pahoehoe lavas are more primitive with higher contents of MgO. The emplacement of compound pahoehoe flows is related to low volume eruptions, while sheet lavas were emplaced during sustained eruptions. In contrast, Unit II is formed by thick simple rubbly lavas, characterized by a massive core and a brecciated/rubbly top. Petrographically these flows are characterized by plagioclase-phyric to aphyric basalts with high density of plagioclase crystals in the matrix. Chemically they are more differentiated lavas, and the emplacement is related to sustained high effusion rate eruptions. Both units are low TiO2 and have geochemical characteristics of Gramado magma type. The Torres Syncline main valley has a similar evolution when compared to other Large Igneous Provinces

  16. Deformation Analysis of Curved Folds in the Southern Upper Magdalena Valley. Colombia

    NASA Astrophysics Data System (ADS)

    Jimenez, G.; Bayona, G. A.; Silva, C.; Rapalini, A.; Trindade, R.

    2008-12-01

    In the Upper Magdalena Valley of Colombia there are folds with changes in the strike of their axes (e.g La Hocha Anticline), the origin of which was studied by integrating field, paleomagnetic and magnetic anisotropy data. Two structural domains were defined: the northern is a symmetrical fold and has a strike N10W, whereas the southern is an asymmetrical fold and has a N30E strike. The principal fault is the San Jacinto Fault, which is a reverse fault with slikensides indicating also a horizontal component of displacement. In the hanging wall of the San Jacinto Fault Mesozoic rocks crops out forming an anticline, whereas in the footwall Cenozoic rocks with vertical and locally overturned beds are exposed. Four magnetic components were isolated, being the low coercivity/temperature component similar to the present field. A characteristic component isolated in Cretaceous and Cenozoic rocks is a pre-fold but post-Oligocene component (n=5, D=0.8, I=2.4, K=62.33, a95=9.8). Two characteristic components were isolated in Jurassic rocks. The directions of the first are similar between domains (north domain: n=10 D=20.7 I=35.6 K=13 a95=12.5; south domain: n=6 D=12 I=28.9 K=16 a95=9.5), suggesting no relationship between strike changes and declination variation. The other component has negative inclination (n=2 D=13.8 I=-27.1 K=61.42 a95=11.8) indicating a mean paleolatitude of 14.4S in Jurassic time. Paleomagnetic data suggest that the curved fold is controlled by the geometry of the paleobasin and support the northward translation of accreted terranes along the Western margin of South America during the Jurassic. Anisotropy of magnetic susceptibility analysis in Jurassic and Cretaceous rocks document three magnetic fabrics: (1) Undeformed fabrics are located in the back limb of La Hocha Anticline; (2) tectonics fabrics are associated to reverse fault planes in the north and south domains and indicated a relationship between the anisotropy ellipsoid with the local stress

  17. Geometry, Timing, and Rates of Active Northeast Tilting Across the Southern Coachella Valley and Santa Rosa Mountains

    NASA Astrophysics Data System (ADS)

    Dorsey, R. J.; Langenheim, V. E.; McNabb, J. C.

    2012-12-01

    The Coachella Valley occupies an important transition along the San Andreas fault (SAF) from strong transpression in the north to transtension and lithospheric rupture in the south. The deformation processes and crustal architecture that accommodate this transition are not well understood. Geomorphic, stratigraphic, and gravity data support a hypothesis for northeast tilting of a large tilt block in the southern Coachella Valley and Santa Rosa Mountains, between the San Jacinto fault zone on the SW (dated in other studies at ~1.2 Ma) and the SAF on the NE. The Santa Rosa fault (SRF) is a strand of the San Jacinto fault zone that marks the steep SW flank of the Santa Rosa Mts and merges with the Clark fault beneath Clark Valley. The SRF is an active normal fault with well developed triangular facets, steeply SW-dipping fault zone with brittle gouge and microfaults, and narrow footwall canyons that feed steep alluvial fans in the hanging wall (east side of Clark Valley). Pliocene marine deposits have been raised by Quaternary uplift in the footwall of the SRF to ~625 m elevation in the Santa Rosa Mts (King et al., 2002). The subsurface Clark basin is ~4 km deep, and the pre-SRF West Salton detachment fault projects ~1.5 km above the valley floor in the Santa Rosa Mts. A steep linear gravity gradient reveals combined vertical separation of ~5.5 km across the SRF and Clark fault, for an average slip rate of ~4.5 mm/yr across the two faults. The NE side of the Santa Rosa Mts has a gentler surface gradient and no large-offset active faults. The ratio of alluvial fan area to catchment area is 0.5-0.6 for fan-catchment pairs along the SRF, compared to an average of ~1.1-1.2 on the NE slope of the Santa Rosa Mts. The different ratios suggest rapid subsidence in the hanging wall of the SRF and relatively slow subsidence in the NE-tilting footwall (cf. Allen and Hovius, 1998). The depth of the southern Coachella Valley increases from the SW side, where sediments onlap

  18. The Salton Seismic Imaging Project: Tomographic characterization of a sediment-filled rift valley and adjacent ranges, southern California

    NASA Astrophysics Data System (ADS)

    Davenport, K.; Hole, J. A.; Stock, J. M.; Fuis, G. S.; Carrick, E.; Tikoff, B.

    2011-12-01

    The Salton Trough in Southern California represents the northernmost rift of the Gulf of California extensional system. Relative motion between the Pacific and North American plates is accommodated by continental rifting in step-over zones between the San Andreas, Imperial, and Cerro Prieto transform faults. Rapid sedimentation from the Colorado River has isolated the trough from the southern portion of the Gulf of California, progressively filling the subsiding rift basin. Based on data from previous seismic surveys, the pre-existing continent has ruptured completely, and a new ~22 km thick crust has been created entirely by sedimentation overlying rift-related magmatism. The MARGINS, EarthScope, and USGS-funded Salton Seismic Imaging Project (SSIP) was designed to investigate the nature of this new crust, the ongoing process of continental rifting, and associated earthquake hazards. SSIP, acquired in March 2011, comprises 7 lines of onshore seismic refraction / wide-angle reflection data, 2 lines of refraction / reflection data in the Salton Sea, and a line of broadband stations. This presentation focuses on the refraction / wide-angle reflection line across the Imperial Valley, extending ~220 km across California from Otay Mesa, near Tijuana, to the Colorado River. The data from this line includes seventeen 100-160 kg explosive shots and receivers at 100 m spacing across the Imperial Valley to constrain the structure of the Salton Trough rift basin, including the Imperial Fault. Eight larger shots (600-920 kg) at 20-35 km spacing and receivers at 200-500 m spacing extend the line across the Peninsular Ranges and the Chocolate Mountains. These data will contrast the structure of the rift to that of the surrounding crust and provide constraints on whole-crust and uppermost mantle structure. Preliminary work has included tomographic inversion of first-arrival travel times across the Valley, emphasizing a minimum-structure approach to create a velocity model of the

  19. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    SciTech Connect

    J.M. Thomas; F.C. Benedict, Jr.; T.P. Rose; R.L. Hershey; J.B. Paces; Z.E. Peterman; I.M. Farnham; K.H. Johannesson; A.K. Singh; K.J. Stetzenbach; G.B. Hudson; J.M. Kenneally; G.F. Eaton; D.K. Smith

    2003-01-08

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units.

  20. Seismic calibration shots conducted in 2009 in the Imperial Valley, southern California, for the Salton Seismic Imaging Project (SSIP)

    USGS Publications Warehouse

    Murphy, Janice; Goldman, Mark; Fuis, Gary; Rymer, Michael; Sickler, Robert; Miller, Summer; Butcher, Lesley; Ricketts, Jason; Criley, Coyn; Stock, Joann; Hole, John; Chavez, Greg

    2011-01-01

    Rupture of the southern section of the San Andreas Fault, from the Coachella Valley to the Mojave Desert, is believed to be the greatest natural hazard facing California in the near future. With an estimated magnitude between 7.2 and 8.1, such an event would result in violent shaking, loss of life, and disruption of lifelines (freeways, aqueducts, power, petroleum, and communication lines) that would bring much of southern California to a standstill. As part of the Nation's efforts to prevent a catastrophe of this magnitude, a number of projects are underway to increase our knowledge of Earth processes in the area and to mitigate the effects of such an event. One such project is the Salton Seismic Imaging Project (SSIP), which is a collaborative venture between the United States Geological Survey (USGS), California Institute of Technology (Caltech), and Virginia Polytechnic Institute and State University (Virginia Tech). This project will generate and record seismic waves that travel through the crust and upper mantle of the Salton Trough. With these data, we will construct seismic images of the subsurface, both reflection and tomographic images. These images will contribute to the earthquake-hazard assessment in southern California by helping to constrain fault locations, sedimentary basin thickness and geometry, and sedimentary seismic velocity distributions. Data acquisition is currently scheduled for winter and spring of 2011. The design and goals of SSIP resemble those of the Los Angeles Region Seismic Experiment (LARSE) of the 1990's. LARSE focused on examining the San Andreas Fault system and associated thrust-fault systems of the Transverse Ranges. LARSE was successful in constraining the geometry of the San Andreas Fault at depth and in relating this geometry to mid-crustal, flower-structure-like decollements in the Transverse Ranges that splay upward into the network of hazardous thrust faults that caused the 1971 M 6.7 San Fernando and 1987 M 5

  1. Inventory of San Joaquin kit fox on BLM lands in southern and southwestern San Joaquin Valley. Final report

    SciTech Connect

    O'Farrell, T.P.; Kato, T.; McCue, P.; Sauls, M.L.

    1980-08-01

    The objectives of this study were to provide the Bureau of Land Management, Bakersfield District, with information on the distribution of the San Joaquin kit fox, an endangered species, on public lands in the southern and southwestern San Joaquin Valley of California, and to develop information essential for designating kit fox critical habitats on lands under their jurisdiction as outlined by the Endangered Species Act and its amendments. A total of 31,860 acres of BLM lands were surveyed using line transects at a density of 8 per linear mile. Observations were recorded on: (1) kit fox dens, tracks, scats, and remains of their prey; (2) vegetation associations; (3) topography; (4) evidence of human activities; (5) species composition and abundance of wildlife seen, especially lagomorphs; (6) presence of Eriogonum gossypinum, a plant of special interest; and (7) presence of the blunt-nosed leopard lizard, another endangered species.

  2. Factors motivating Latino college students to pursue STEM degrees on CSU campuses in the southern San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Ramirez, Gabriel

    The purpose of this study was to determine what factors were motivating Latino/a students in the southern San Joaquin Valley to pursue STEM degrees and whether these factors were specific to the Latino/a culture. A 12-question survey was administered to STEM majors at California State University, Bakersfield and California State University, Fresno and interviews were conducted with those survey respondents who agreed to be part of the process. The results of the survey suggested that factors such as STEM subject matter, STEM career knowledge, the possibility of a high paying salary, high school STEM grades, and family influence were significant in motivating Latino/a students to pursue STEM degrees. The results of the Chi Square Test suggested the Latino/a students' responses about college STEM degree granting statistics, the possibility of a high salary, and the effects of setbacks were significantly different to those of their non-Latino/a counterparts.

  3. Observational constraints on projections of the ozone response to NOx controls in the Southern San Joaquin Valley

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Wooldridge, P. J.; Browne, E. C.; Russell, A. R.; Rollins, A.; Min, K.; Thomas, J.; Zhang, L.; Brune, W. H.; Henry, S. B.; DiGangi, J. P.; Keutsch, F. N.; Sanders, J. E.; Ren, X.; Weber, R.; Goldstein, A. H.; Cohen, R. C.

    2011-12-01

    We investigate the impact of NOx reductions on ozone production in the Southern San Joaquin Valley using a large suite of radical and trace gas measurements collected during CalNex-2010 in Bakersfield, California (May 15-June 28) combined with the historical record of O3, nitrogen oxides and temperature from CARB monitoring sites in the region. We calculate the instantaneous ozone production rate (PO3) by radical balance and investigate relationships between PO3 and NOx abundance; finding temperature to be a useful proxy for VOC reactivity. We show Bakersfield photochemistry is at peak PO3 and therefore at a minimum with respect to the effectiveness of NOx controls indicating: (1) more than 30% reductions from present day are required before sizable decreases in ozone will occur and (2) reduction from the lower weekend baseline NOx concentrations will result in weekend PO3 decreases with continued NOx controls at high temperatures when VOC reactivity is largest.

  4. Topographic growth around the Orange River valley, southern Africa: A Cenozoic record of crustal deformation and climatic change

    NASA Astrophysics Data System (ADS)

    Dauteuil, Olivier; Bessin, Paul; Guillocheau, François

    2015-03-01

    We reconstruct the history of topographic growth in southern Africa on both sides of the Orange River valley from an integrated analysis of erosion surfaces, crustal deformation and climate change. First, we propose an inventory of erosion surfaces observed in the study area and classify them according to their most likely formative process, i.e. chemical weathering or mechanical erosion. Among the various land units observed we define a new class of landform: the pedivalley, which corresponds to a wide valley with a flat erosional floor. In the Orange River valley, we mapped three low-relief erosion surfaces, each bevelling a variety of lithologies. The oldest and most elevated is (1) a stripped etchplain evolving laterally into (2) a stepped pediplain bearing residual inselbergs; (3) a younger pediplain later formed in response to a more recent event of crustal deformation. These are all Cenozoic landforms: the etchplain is associated with a late Palaeocene to middle Eocene weathering event, and the two pediplains are older than the middle Miocene alluvial terraces of the Orange River. Landscape evolution was first driven by slow uplift (10 m/Ma), followed by a second interval of uplift involving a cumulative magnitude of at least 200 m. This event shaped the transition between the two pediplains and modified the drainage pattern. A final phase of uplift (magnitude: 60 m) occurred after the Middle Miocene and drove the incision of the lower terraces of the Orange River. Climate exerted a major control over the denudation process, and involved very humid conditions responsible for lateritic weathering, followed by more arid conditions, which promoted the formation of pedivalleys. Collectively, these produce pediplains.

  5. Geologic map of the southern Funeral Mountains including nearby groundwater discharge sites in Death Valley National Park, California and Nevada

    USGS Publications Warehouse

    Fridrich, C.J.; Thompson, R.A.; Slate, J.L.; Berry, M.E.; Machette, M.N.

    2012-01-01

    This 1:50,000-scale geologic map covers the southern part of the Funeral Mountains, and adjoining parts of four structural basins—Furnace Creek, Amargosa Valley, Opera House, and central Death Valley—in California and Nevada. It extends over three full 7.5-minute quadrangles, and parts of eleven others—an area of about 1,000 square kilometers (km2). The boundaries of this map were drawn to include all of the known proximal hydrogeologic features that may affect the flow of groundwater that discharges from springs of the Furnace Creek basin, in the west-central part of the map. These springs provide the main potable water supply for Death Valley National Park. Major hydrogeologic features shown on this map include: (1) springs of the Furnace Creek basin, (2) a large Pleistocene groundwater discharge mound in the northeastern part of the map, (3) the exposed extent of limestones and dolomites that constitute the Paleozoic carbonate aquifer, and (4) the exposed extent of the alluvial conglomerates that constitute the Funeral Formation aquifer.

  6. Geomorphic and sedimentary responses of the Bull Creek Valley (Southern High Plains, USA) to Pleistocene and Holocene environmental change

    NASA Astrophysics Data System (ADS)

    Arauza, Hanna M.; Simms, Alexander R.; Bement, Leland C.; Carter, Brian J.; Conley, Travis; Woldergauy, Ammanuel; Johnson, William C.; Jaiswal, Priyank

    2016-01-01

    Fluvial geomorphology and stratigraphy often reflect past environmental and climate conditions. This study examines the response of Bull Creek, a small ephemeral creek in the Oklahoma panhandle, to environmental conditions through the late Pleistocene and Holocene. Fluvial terraces were mapped and their stratigraphy and sedimentology documented throughout the course of the main valley. Based on their elevations, terraces were broadly grouped into a late-Pleistocene fill terrace (T3) and two Holocene fill-cut terrace sets (T2 and T1). Terrace systems are marked by similar stratigraphies recording the general environmental conditions of the time. Sedimentary sequences preserved in terrace fills record the transition from a perennial fluvial system during the late glacial period and the Younger Dryas to a semiarid environment dominated by loess accumulation and punctuated by flood events during the middle to late Holocene. The highest rates of aeolian accumulation within the valley occurred during the early to middle Holocene. Our data provide significant new information regarding the late-Pleistocene and Holocene environmental history for this region, located between the well-studied Southern and Central High Plains of North America.

  7. Geophysical Studies in the Vicinity of the Warner Mountains and Surprise Valley, Northeast California, Northwest Nevada, and Southern Oregon

    USGS Publications Warehouse

    Ponce, David A.; Glen, Jonathan M.G.; Egger, Anne E.; Bouligand, Claire; Watt, Janet T.; Morin, Robert L.

    2009-01-01

    From May 2006 to August 2007, the U.S. Geological Survey (USGS) collected 793 gravity stations, about 102 line-kilometers of truck-towed and ground magnetometer data, and about 325 physical-property measurements in northeastern California, northwestern Nevada, and southern Oregon. Gravity, magnetic, and physical-property data were collected to study regional crustal structures and geology as an aid to understanding the geologic framework of the Surprise Valley geothermal area and, in general, geothermal systems throughout the Great Basin. The Warner Mountains and Surprise Valley mark the transition from the extended Basin and Range province to the unextended Modoc Plateau. This transition zone, in the northwestern corner of the Basin and Range, is relatively diffuse compared to other, more distinct boundaries, such as the Wasatch front in Utah and the eastern Sierran range front. In addition, this transition zone is the site of a geothermal system with potential for development, and previous studies have revealed a complex structural setting consisting of several obliquely oriented fault sets. As a result, this region has been the subject of several recent geological and geophysical investigations. The gravity and magnetic data presented here support and supplement those studies, and although the study area is composed predominantly of Tertiary volcanic rocks of the Modoc Plateau rocks, the physical properties of these and others rocks create a distinguishable pattern of gravity and magnetic anomalies that can be used to infer subsurface geologic structure.

  8. Thrust faults of southern Diamond Mountains, central Nevada: Implications for hydrocarbons in Diamond Valley and at Yucca Mountain

    SciTech Connect

    French, D.E.

    1993-04-01

    Overmature Mississippian hydrocarbon source rocks in the southern Diamond Mountains have been interpreted to be a klippe overlying less mature source rocks and represented as an analogy to similar conditions near Yucca Mountain (Chamberlain, 1991). Geologic evidence indicates an alternative interpretation. Paleogeologic mapping indicates the presence of a thrust fault, referred to here as the Moritz Nager Thrust Fault, with Devonian rocks emplaced over Permian to Mississippian strata folded into an upright to overturned syncline, and that the overmature rocks of the Diamond Mountains are in the footwall of this thrust. The upper plate has been eroded from most of the Diamond Mountains but remnants are present at the head of Moritz Nager Canyon and at Sentinel Mountain. Devonian rocks of the upper plate comprised the earliest landslide megabreccia. Later, megabreccias of Pennsylvanian and Permian rocks of the overturned syncline of the lower plate were deposited. By this interpretation the maturity of lower-plate source rocks in the southern Diamond Mountains, which have been increased by tectonic burial, is not indicative of conditions in Diamond Valley, adjacent to the west, where upper-plate source rocks might be present in generating conditions. The interpretation that overmature source rocks of the Diamond Mountains are in a lower plate rather than in a klippe means that this area is an inappropriate model for the Eleana Range near Yucca Mountain.

  9. Local pattern of stress field and seismogenic sources in the Pergola-Melandro basin and the Agri valley (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Cucci, Luigi; Pondrelli, Silvia; Frepoli, Alberto; Mariucci, Maria Teresa; Moro, Marco

    2004-03-01

    Our study area is a ca 50 km long section of the central-southern Apennines tectonic belt that includes the Pergola-Melandro basin (PM) and the Agri valley (AV). This region is located between the areas affected by the 1980 Ms= 6.9 Irpinia and the 1857 M= 7.0 val d'Agri earthquakes and is characterized by rare historical events and very low and sparse background seismicity. In this study we provide new seismological and geophysical information to identify the characteristics of the seismotectonics in the area as the prevailing faulting mechanism and the fit of local to regional stress field. These data concern focal mechanisms from waveform modelling and P-wave polarities, analyses of borehole breakouts and detailed investigation of two seismic sequences. All the data cover a significantly broad range of magnitudes and depths and suggest that no important local variation in stress orientation seems to affect this area, which shows a NE-SW direction of extension consistent with that regionally observed in southern Italy. Such local homogeneity in the stress field pattern is peculiar to the study area; the variations of orientation and/or type of stress observed in the northern Apennines, or less than only 100 km toward the northwest within the same tectonic belt, are absent here. Furthermore, there is a suggestion for a northeastward sense of dip of the seismogenic faults in the region, an interesting constraint to the characterization of seismic sources.

  10. Geology and geophysics of the southern Raft River Valley geothermal area, Idaho, USA

    USGS Publications Warehouse

    Williams, Paul L.; Mabey, Don R.; Zohdy, Adel A.R.; Hans, Ackerman; Hoover, Donald B.; Pierce, Kenneth L.; Oriel, Steven S.

    1976-01-01

    The Raft River valley, near the boundary of the Snake River plain with the Basin and Range province, is a north-trending late Cenozoic downwarp bounded by faults on the west, south, and east. Pleistocene alluvium and Miocene-Pliocene tuffaceous sediments, conglomerate, and felsic volcanic rocks aggregate 2 km in thickness. Large gravity, magnetic, and total field resistivity highs probably indicate a buried igneous mass that is too old to serve as a heat source. Differing seismic velocities relate to known or inferred structures and to a suspected shallow zone of warm water. Resistivity anomalies reflect differences of both composition and degree of alteration of Cenozoic rocks. Resistivity soundings show a 2 to 5 ohm·m unit with a thickness of 1 km beneath a large part of the valley, and the unit may indicate partly hot water and partly clayey sediments. Observed self-potential anomalies are believed to indicate zones where warm water rises toward the surface. Boiling wells at Bridge, Idaho are near the intersection of north-northeast normal faults which have moved as recently as the late (?) Pleistocene, and an east-northeast structure, probably a right-lateral fault. Deep circulation of ground water in this region of relatively high heat flow and upwelling along faults is the probable cause of the thermal anomaly.

  11. Carbon and Isotopic Mass Balance Models of Oasis Valley-Fortymile Canyon Groundwater Basin, Southern Nevada

    NASA Astrophysics Data System (ADS)

    White, Art F.; Chuma, Nancy J.

    1987-04-01

    Environmental isotopes and carbon chemistry provide means of differentiating various recharge areas, flow paths, and ages of groundwater in portions of the Nevada Test Site and vicinity. Regional δD/δ18O trends are offset from the present-day meteoric line by a deuterium depletion of 5‰, suggesting paleoclimatic changes. Partial pressures of CO2 and the 18O and 13C data indicate solubility and isotopic equilibrium between the gas and water in the soil zone with progressive exchange with underlying groundwater in the shallow alluvium of Oasis Valley. Application of a closed system CO2 model using the EQ3NR/EQ6 reaction path simulator successfully reproduces chemical compositions observed in the alluvium in the Amargosa Desert and in the deep tuff aquifer beneath Pahute Mesa and Yucca Mountain. Initial PCO2 input to the soil zone during recharge was calculated to range from 0.03 to 0.10 atm, which is comparable to measured soil CO2 pressures in Oasis Valley. Results are compared for 14C ages using the δ13C dilution correction and a mass action correction term relating predicted and calculated ionic activity products of CaCO3. Results are generally comparable with discrepancies attributed to anomalous δ13C values.

  12. Pliocene transpressional modification of depositional basins by convergent thrusting adjacent to the "Big Bend" of the San Andreas fault: An example from Lockwood Valley, southern California

    USGS Publications Warehouse

    Kellogg, K.S.; Minor, S.A.

    2005-01-01

    The "Big Bend" of the San Andreas fault in the western Transverse Ranges of southern California is a left stepping flexure in the dextral fault system and has long been recognized as a zone of relatively high transpression compared to adjacent regions. The Lockwood Valley region, just south of the Big Bend, underwent a profound change in early Pliocene time (???5 Ma) from basin deposition to contraction, accompanied by widespread folding and thrusting. This change followed the recently determined initiation of opening of the northern Gulf of California and movement along the southern San Andreas fault at about 6.1 Ma, with the concomitant formation of the Big Bend. Lockwood Valley occupies a 6-km-wide, fault-bounded structural basin in which converging blocks of Paleoproterozoic and Cretaceous crystalline basement and upper Oligocene and lower Miocene sedimentary rocks (Plush Ranch Formation) were thrust over Miocene and Pliocene basin-fill sedimentary rocks (in ascending order, Caliente Formation, Lockwood Clay, and Quatal Formation). All the pre-Quatal sedimentary rocks and most of the Pliocene Quatal Formation were deposited during a mid-Tertiary period of regional transtension in a crustal block that underwent little clockwise vertical-axis rotation as compared to crustal blocks to the south. Ensuing Pliocene and Quaternary transpression in the Big Bend region began during deposition of the poorly dated Quatal Formation and was marked by four converging thrust systems, which decreased the areal extent of the sedimentary basin and formed the present Lockwood Valley structural basin. None of the thrusts appears presently active. Estimated shortening across the center of the basin was about 30 percent. The fortnerly defined eastern Big Pine fault, now interpreted to be two separate, oppositely directed, contractional reverse or thrust faults, marks the northwestern structural boundary of Lockwood Valley. The complex geometry of the Lockwood Valley basin is similar

  13. Geomorphology and Tectonics at the Intersection of Silurian and Death Valleys, Southern California - 2005 Guidebook Pacific Cell Friends of the Pleistocene

    USGS Publications Warehouse

    Miller, David M.; Valin, Zenon C.

    2007-01-01

    This publication describes results from new regional and detailed surficial geologic mapping, combined with geomorphologic, geochronologic, and tectonic studies, in Silurian Valley and Death Valley, California. The studies address a long-standing problem, the tectonic and geomorphic evolution of the intersection between three regional tectonic provinces: the eastern California shear zone, the Basin and Range region of southern Nevada and adjacent California, and the eastern Mojave Desert region. The chapters represent work presented on the 2005 Friends of the Pleistocene field trip and meeting as well as the field trip road log.

  14. Characterizing the hydrogeologic framework of the Death Valley region, Southern Nevada and California

    USGS Publications Warehouse

    Faunt, Claudia; D'Agnese, Frank; Downey, Joe S.; Turner, A. Keith

    1993-01-01

    Three-dimensional (3-D) hydrogeologic modeling of the complex geology of the Death Valley region requires the application of a number of Geoscientific Information System (GSIS) techniques. This study, funded by United States Department of Energy as a part of the Yucca Mountain Project, focuses on an area of approximately 100,000 square kilometers (three degrees of latitude by three degrees of longitude) and extends up to ten kilometers in depth. The geologic conditions are typical of the Basin and Range province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. GSIS techniques allow the synthesis of geologic, hydrologic and climatic information gathered from many sources, including satellite imagery and published maps and cross-sections. Construction of a 3-D hydrogeological model is possible with the combined use of software products available from several vendors, including traditional GIS products and sophisticated contouring, interpolation, visualization, and numerical modeling packages.

  15. Ozone Production in the Southern San Joaquin Valley: A NOx Perspective

    NASA Astrophysics Data System (ADS)

    Pusede, S. E.; Wooldridge, P. J.; Browne, E. C.; Rollins, A. W.; Min, K.; Cohen, R. C.; Baier, B. C.; Beaver, M. R.; Boyle, E.; Brune, W. H.; Digangi, J. P.; Gentner, D. R.; Goldstein, A. H.; Keutsch, F.; Ren, X.; Sanders, J.; St Clair, J. M.; Thomas, J.; Weber, R.; Wennberg, P. O.; Zhang, L.

    2010-12-01

    We present measurements of NO2, total alkyl nitrates (ΣANs), and HNO3 by thermal dissociation-laser induced fluorescence (TD-LIF) and NO by chemiluminescence made as part of CalNex-2010 at the San Joaquin Valley supersite in Bakersfield, California (May 15-June 28). We discuss these nitrogen oxide observations in the context of co-located OH, HO2, HONO, H2CO, H2O2, VOC, and O3 measurements, examining the instantaneous ozone production rate (PO3) as a function of NO concentration and HOx production rate. Furthermore, using the slope of the Ox/ΣANs correlation, we report the lowest ever observed urban ΣANs branching ratio (1.5-2%). We test our understanding of this chemistry with a photochemical model, evaluating the implications of suppressed alkyl nitrate formation on O3 production.

  16. Geophysical Studies Based on Gravity and Seismic Data of Tule Desert, Meadow Valley Wash, and California Wash Basins, Southern Nevada

    USGS Publications Warehouse

    Scheirer, Daniel S.; Page, William R.; Miller, John J.

    2006-01-01

    Gravity and seismic data from Tule Desert, Meadow Valley Wash, and California Wash, Nevada, provide insight into the subsurface geometry of these three basins that lie adjacent to rapidly developing areas of Clark County, Nevada. Each of the basins is the product of Tertiary extension accommodated with the general form of north-south oriented, asymmetrically-faulted half-grabens. Geophysical inversion of gravity observations indicates that Tule Desert and Meadow Valley Wash basins are segmented into subbasins by shallow, buried basement highs. In this study, basement refers to pre-Cenozoic bedrock units that underlie basins filled with Cenozoic sedimentary and volcanic units. In Tule Desert, a small, buried basement high inferred from gravity data appears to be a horst whose placement is consistent with seismic reflection and magnetotelluric observations. Meadow Valley Wash consists of three subbasins separated by basement highs at structural zones that accommodated different styles of extension of the adjacent subbasins, an interpretation consistent with geologic mapping of fault traces oblique to the predominant north-south fault orientation of Tertiary extension in this area. California Wash is a single structural basin. The three seismic reflection lines analyzed in this study image the sedimentary basin fill, and they allow identification of faults that offset basin deposits and underlying basement. The degree of faulting and folding of the basin-fill deposits increases with depth. Pre-Cenozoic units are observed in some of the seismic reflection lines, but their reflections are generally of poor quality or are absent. Factors that degrade seismic reflector quality in this area are rough land topography due to erosion, deformed sedimentary units at the land surface, rock layers that dip out of the plane of the seismic profile, and the presence of volcanic units that obscure underlying reflectors. Geophysical methods illustrate that basin geometry is more

  17. Constraints on the post-middle-Pleistocene tectonic development of the Confidence Hills, southern Death Valley, California

    NASA Astrophysics Data System (ADS)

    Goodman, J. T.; Caskey, S. J.

    2009-12-01

    Our recent field mapping and tephrochronology offers new constraints on the style, timing, and rates of middle-Pleistocene-to-recent deformation in the Confidence Hills (CH), southern Death Valley. Movement on the active trace of the Southern Death Valley fault zone (SDVFZ) was preceded by earlier large-scale, northeast-vergent folding. This earlier folding involves several hundred meters of conformable late-Pliocene-to-middle-Pleistocene strata, which together form the common limb of a locally overturned fault-propagation fold pair. Geometric relations require that the blind thrust(s) responsible for earlier folding in the CH root well to the southwest of the active trace of the SDVFZ, which raises questions concerning previous flower structure models for earlier folding in the CH. Earlier folding began after deposition of Upper Glass Mountain tephra (1.1-0.9 Ma), which lies within the uppermost section of conformable, locally overturned Confidence Hills Formation(CHF), and ended prior to deposition of unconformably overlying fanglomerate, which contain tephra layers we tentatively correlate to the Bishop (0.76 Ma) and Lava Creek B (0.64 Ma) tephra. Earlier folding resulted in greater than 400 m structural relief and nearly 600 m of shortening in the span of 140-340 ka, yielding a middle-Pleistocene shortening rate of ~1.8-4.3 mm/yr. Dextral slip along the mappable traces of the SDVFZ began after earlier fault-propagation folding and also after deposition of the 0.76-0.64-Ma fanglomerates. Net right-lateral offset along the fault zone is well constrained ~4-km south of Shoreline Butte where a steeply-dipping contact marking the base of volcaniclastic conglomerate of the CHF is offset ~650 m. These relations yield a minimum post-middle-Pleistocene slip rate of ~1 mm/yr for the SDVFZ. Post-0.64-Ma shortening within the CH has been minor relative to earlier folding. The earlier fault-propagation folding in the CH appears to be related to a short-lived episode of

  18. Valley Crossing

    NASA Technical Reports Server (NTRS)

    2005-01-01

    24 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the walls and floor of a valley in the western Memnonia region of Mars. The finely-textured ridges and pits found on the valley walls and upland outside of the valley were formed by wind erosion.

    Location near: 487.5oS, 155.8oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Spring

  19. High-precision U-Pb geochronology in the Minnesota River Valley subprovince and its bearing on the Neoarchean to Paleoproterozoic evolution of the southern Superior Province

    USGS Publications Warehouse

    Schmitz, M.D.; Bowring, S.A.; Southwick, D.L.; Boerboom, Terrence; Wirth, K.R.

    2006-01-01

    High-precision U-Pb ages have been obtained for high-grade gneisses, late-kinematic to postkinematic granitic plutons, and a crosscutting mafic dike of the Archean Minnesota River Valley tectonic subprovince, at the southern ramparts of the Superior craton of North America. The antiquity of the Minnesota River Valley terranes is confirmed by a high-precision U-Pb zircon age of 3422 ?? 2 Ma for a tonalitic phase of the Morton Gneiss. Voluminous, late-kinematic monzogranites of the Benson (Ortonville granite) and Morton (Sacred Heart granite) blocks yield identical crystallization ages of 2603 ?? 1 Ma, illustrating the synchrony and rapidity of deep crustal melting and plutonism throughout the Minnesota River Valley terranes. Postkinematic, 2591 ?? 2 Ma syenogranites and aplitic dikes in both blocks effectively constrain the final penetrative deformation of the Minnesota River Valley subprovince. Monazite growth from 2609 to 2595 Ma in granulitic paragneisses of the Benson and Montevideo blocks is interpreted to record prograde to peak granulite facies metamorphic conditions associated with crustal thickening and magmatism. Neoarchean metamorphism and plutonism are interpreted to record the timing of collisional accretion and terminal suturing of the Mesoarchean continental Minnesota River Valley terranes to the southern margin of the Superior Province, along the western Great Lakes tectonic zone. Subsequent Paleoproterozoic rifting of this margin is recorded by voluminous basaltic dike intrusion, expressed in the Minnesota River Valley by major WNW-trending tholeiitic diabase dikes dated at 2067 ?? 1 Ma, only slightly younger than the structurally and geochemically similar 2077 ?? 4 Ma Fort Frances (Kenora-Kabetogama) dike swarm of northern Minnesota and adjoining Canada. ?? 2006 Geological Society of America.

  20. Early Eocene Molluscan biostratigraphy, Mount Pinos-Lockwood Valley area, northern Ventura County, southern California

    SciTech Connect

    Squires, R.L.; Wilson, M.

    1987-05-01

    A 600-m thick unnamed marine, predominantly transition-zone siltstone unit along the south flank of the Mount Pinos uplift, in the northern Lockwood Valley area, previously has been suggested to be early Eocene (Capay Stage) in age at its base. This present study shows the entire unit to be this age. Unconformably overlying the pre-Tertiary granite basement is 30 m of unfossiliferous muddy siltstone that grades upward into 50 m of very fine sandstone with rarely fossiliferous lenses of medium to coarse sandstone. Gradationally above the sandstone is 100 m of muddy siltstone with less rarely fossiliferous lenses of conglomeratic sandstone. Macrofossil collections made at 10 localities in these lower 180 m yielded a sparse fauna of subtropical shallow-marine gastropods and bivalves, as well as rare specimens of discocyclinid foraminifera. from 180 to 500 m above the base of the section is unfossiliferous siltstone with local occurrences of lower shoreface, alternating laminated and bioturbated very fine sandstone. The uppermost 100 m of the section is siltstone with rarely fossiliferous lenses of fine to medium sandstone. Collections made at five localities yielded subtropical shallow-marine mollusks. Evidence of a West Coast provincial molluscan Capay Stage (early Eocene) age for all the fossiliferous beds of the siltstone unit is the presence of Turritella andersoni, a species diagnostic of this stage. Commonly associated mollusks are Cryptoconus cooperi, Cylichnina tantilla, Ectinochilus (Macilentos) macilentus, and Turritella buwaldana. Unconformably overlying the unit is the Oligocene-lower Miocene nonmarine Plush Ranch Formation.

  1. A Study of the Connection Among Basin-Fill Aquifers, Carbonate-Rock Aquifers, and Surface-Water Resources in Southern Snake Valley, Nevada

    USGS Publications Warehouse

    ,

    2008-01-01

    The Secretary of the Interior through the Southern Nevada Public Lands Management Act approved funding for research to improve understanding of hydrologic systems that sustain numerous water-dependent ecosystems on Federal lands in Snake Valley, Nevada. Some of the streams and spring-discharge areas in and adjacent to Great Basin National Park have been identified as susceptible to ground-water withdrawals (Elliott and others, 2006) and research has shown a high potential for ground-water flow from southern Spring Valley into southern Snake Valley through carbonate rocks that outcrop along a low topographic divide known as the Limestone Hills (Welch and others, 2007). Comprehensive geologic, hydrologic, and chemical information will be collected and analyzed to assess the hydraulic connection between basin-fill aquifers and surface-water resources, water-dependent ecological features, and the regional carbonate-rock aquifer, the known source of many high-discharge springs. Understanding these connections is important because proposed projects to pump and export ground water from Spring and Snake Valleys in Nevada may result in unintended capture of water currently supplying springs, streams, wetlands, limestone caves, and other biologically sensitive areas (fig. 1). The methods that will be used in this study may be transferable to other areas in the Great Basin. The National Park Service, Bureau of Land Management, U.S. Fish and Wildlife Service, and U.S. Forest Service submitted the proposal for funding this research to facilitate science-based land management. Scientists from the U.S. Geological Survey (USGS) Water Resources and Geologic Disciplines, and the University of Nevada, Reno, will accomplish four research elements through comprehensive data collection and analysis that are concentrated in two distinct areas on the eastern and southern flanks of the Snake Range (fig. 2). The projected time line for this research is from July 2008 through September 2011.

  2. Aquatic Insect Emergence in Post-Harvest Flooded Agricultural Fields in the Southern San Joaquin Valley, California

    NASA Astrophysics Data System (ADS)

    Moss, R. C.; Blumenshine, S.; Fleskes, J.

    2005-05-01

    California's Southern San Joaquin Valley is one of the most important waterbird areas in North America, but has suffered a disproportionate loss of wetlands when compared to other California regions. This project analyzes the habitat value of post-harvest flooded cropland by measuring the emergence of aquatic insects across multiple crop types. Aquatic insect emergence was sampled from post-harvest flooded fields of four crop types (alfalfa, corn, tomato, wheat), August-October, 2003-2004. Emergence was measured using traps deployed with a stratified random distribution to sample between and within field variation. Emergence rate and emergent biomass was significantly higher in flooded tomato fields. Results from corn fields indicate that flooding depth was correlated (r=0.095) with both diel temperature fluctuation and emergence rate. Chironomus dilutus larvae were grown in environmental chambers, under two thermal treatments with the same mean but different amplitudes (high: 15°-32°C, low: 20°-26°C) to investigate thermal fluctuation effects on survival and biomass. Larval survival (4x) and biomass (2x) were significantly greater in the low versus high temperature fluctuation treatment. This research has the potential to affect agricultural management throughout the 12,600 km2 region, increase aquatic insect production and aid in the recovery of declining bird populations.

  3. Paleomagnetic Definition of Domains and Quaternary Block-Rotations in the East Ventura Basin and San Fernando Valley, Southern California

    NASA Astrophysics Data System (ADS)

    Levi, S.; Levi, S.; Yeats, R. S.

    2001-12-01

    The San Fernando Valley and east Ventura basin in southern California, the region of the 1994 Northridge earthquake and the LARSE 2 deep crustal profile, are fragmented into domains up to tens of kilometers in linear dimension. These domains were determined from paleomagnetic studies of the Pliocene-Quaternary Saugus Formation, which was deposited between 2.3 and 0.4 Ma based on a magnetostratigraphic section described by Levi and Yeats (1993, Tectonics). In two of the four domains, southwest of and adjacent to the San Gabriel fault, the Saugus shows significant Quaternary clockwise rotation (Magic Mountain, 30o; Kagel Ridge, 34o). The two other domains are unrotated (Soledad Canyon, northeast of and adjacent to the San Gabriel fault immediately across the fault from the Magic Mountain domain, and the Van Norman reservoir in the south limb of the Mission Hills syncline, directly south of the Santa Susana fault and southeast of the Magic Mountain domain). The fragmentation and clockwise rotation represent crustal response to complex dextral shear between the Pacific and North America plates. The response of individual domains is dictated by their geometry and zones of interaction along boundaries with adjacent domains. The relatively small size of the domains might impose an upper limit on magnitude of local crustal earthquakes.

  4. Geological and geophysical characterization of the south-eastern side of the High Agri Valley (southern Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Giocoli, A.; Stabile, T. A.; Adurno, I.; Perrone, A.; Gallipoli, M. R.; Gueguen, E.; Norelli, E.; Piscitelli, S.

    2014-10-01

    In the frame of a national project funded by Eni S.p.A. and developed by three institutes of the National Research Council (the Institute of Methodologies for Environmental Analysis, the Institute of Research for Hydrogeological Protection and the Institute for Electromagnetic Sensing of the Environment), a multidisciplinary approach based on the integration of satellite, aero-photogrammetric and in situ geophysical techniques was applied to investigate an area located in the Montemurro territory in the south-eastern sector of the High Agri Valley (Basilicata Region, southern Italy). This paper reports the results of the in situ geophysical investigation. Electrical Resistivity Tomography (ERT) and Horizontal to Vertical Spectral Ratio (HVSR) by earthquakes and ambient noise measurements were carried out in the study area. The results were supported by interpretation of aerial photos, geological field surveys, morphotectonic investigation and borehole data. The joint analysis of geological, ERT and HVSR data allowed us to (1) show the shallow geological and structural setting, (2) detect the geometry of the different lithological units and their mechanical and dynamical properties, (3) image a previously unmapped fault beneath suspected scarps/warps and (4) characterize the geometry of an active landslide that caused damages to structures and infrastructures.

  5. Evaluation of the groundwater flow model for southern Utah and Goshen Valleys, Utah, updated to conditions through 2011, with new projections and groundwater management simulations

    USGS Publications Warehouse

    Brooks, Lynette E.

    2013-01-01

    The U.S. Geological Survey (USGS), in cooperation with the Southern Utah Valley Municipal Water Association, updated an existing USGS model of southern Utah and Goshen Valleys for hydrologic and climatic conditions from 1991 to 2011 and used the model for projection and groundwater management simulations. All model files used in the transient model were updated to be compatible with MODFLOW-2005 and with the additional stress periods. The well and recharge files had the most extensive changes. Discharge to pumping wells in southern Utah and Goshen Valleys was estimated and simulated on an annual basis from 1991 to 2011. Recharge estimates for 1991 to 2011 were included in the updated model by using precipitation, streamflow, canal diversions, and irrigation groundwater withdrawals for each year. The model was evaluated to determine how well it simulates groundwater conditions during recent increased withdrawals and drought, and to determine if the model is adequate for use in future planning. In southern Utah Valley, the magnitude and direction of annual water-level fluctuation simulated by the updated model reasonably match measured water-level changes, but they do not simulate as much decline as was measured in some locations from 2000 to 2002. Both the rapid increase in groundwater withdrawals and the total groundwater withdrawals in southern Utah Valley during this period exceed the variations and magnitudes simulated during the 1949 to 1990 calibration period. It is possible that hydraulic properties may be locally incorrect or that changes, such as land use or irrigation diversions, occurred that are not simulated. In the northern part of Goshen Valley, simulated water-level changes reasonably match measured changes. Farther south, however, simulated declines are much less than measured declines. Land-use changes indicate that groundwater withdrawals in Goshen Valley are possibly greater than estimated and simulated. It is also possible that irrigation

  6. Analysis of curved folds and fault/fold terminations in the southern Upper Magdalena Valley of Colombia

    NASA Astrophysics Data System (ADS)

    Jiménez, Giovanny; Rico, John; Bayona, German; Montes, Camilo; Rosero, Alexis; Sierra, Daniel

    2012-11-01

    We use surface and subsurface fold and fault geometries to document curved geometry of folds, along-strike termination of faults/folds and the change of dip of regional faults in four structural areas in the southern part of the Upper Magdalena Valley Basin. In La Cañada area, strike-slip deformation is dominant and cuts former compressional structures; faults and folds of this area end northward abruptly near Rio Paez. To the north of Paez River is the La Hocha area that includes the Tesalia Syncline and La Hocha Anticline, two curved folds that plunge at the same latitude. The southern domain of La Hocha Anticline is asymmetric and bounded by faults in both flanks, whereas the symmetry of the northern domain is related to subsurface fault bending. Paleomagnetic components uncovered in Jurassic rocks suggest a clockwise rotation of 15.2 ± 11.4 in the southern domain, and 31.7 ± 14.4 in the northern domain. The Iquira Area, North of La Hocha, the internal structure is controlled by east-verging faults that end abruptly to the north of this area. The northernmost area is the Upar area that includes fault systems with opposite vergence; west-verging faults at the east of this area decapitate east-verging faults and folds. Paleomagnetic data, geologic mapping and regional structural cross-sections suggest that: (1) pre-existing basement structure controls the curved geometry of La Hocha Anticline; (2) along-strike changes in structural style between adjacent areas and along-strike termination of faults and folds are related to the location of northwest-striking transverse structures in the subsurface; and (3) at least two deformation phases are documented: an Eocene-Oligocene phase associated with the growth of folds along detachment levels within Mesozoic rocks; and a late Miocene phase associated with transpressive faulting along the Chusma and San Jacinto faults. The latter event drove clockwise rotation of the La Hocha Anticline.

  7. Valley-fill alluviation during the Little Ice Age (ca. A.D. 1400-1880), Paria River basin and southern Colorado Plateau, United States

    USGS Publications Warehouse

    Hereford, R.

    2002-01-01

    Valley-fill alluvium deposited from ca. A.D. 1400 to 1880 is widespread in tributaries of the Paria River and is largely coincident with the Little Ice Age epoch of global climate variability. Previous work showed that alluvium of this age is a mappable stratigraphic unit in many of the larger alluvial valleys of the southern Colorado Plateau. The alluvium is bounded by two disconformities resulting from prehistoric and historic arroyo cutting at ca. A.D. 1200-1400 and 1860-1910, respectively. The fill forms a terrace in the axial valleys of major through-flowing streams. This terrace and underlying deposits are continuous and interfinger with sediment in numerous small tributary valleys that head at the base of hillslopes of sparsely vegetated, weakly consolidated bedrock, suggesting that eroded bedrock was an important source of alluvium along with in-channel and other sources. Paleoclimatic and high-resolution paleoflood studies indicate that valley-fill alluviation occured during a long-term decrease in the frequency of large, destructive floods. Aggradation of the valleys ended about A.D. 1880, if not two decades earlier, with the beginning of historic arroyo cutting. This shift from deposition to valley entrenchment near the close of the Little Ice Age generally coincided with the beginning of an episode of the largest floods in the preceding 400-500 yr, which was probably caused by an increased recurrence and intensity of flood-producing El Nin??o events beginning at ca. A.D. 1870.

  8. Estimating sources of Valley Fever pathogen propagation in southern Arizona: A remote sensing approach

    NASA Astrophysics Data System (ADS)

    Pianalto, Frederick S.

    Coccidioidomycosis (Valley Fever) is an environmentally-mediated respiratory disease caused by the inhalation of airborne spores from the fungi Coccidioides spp. The fungi reside in arid and semi-arid soils of the Americas. The disease has increased epidemically in Arizona and other areas within the last two decades. Despite this increase, the ecology of the fungi remains obscure, and environmental antecedents of the disease are largely unstudied. Two sources of soil disturbance, hypothesized to affect soil ecology and initiate spore dissemination, are investigated. Nocturnal desert rodents interact substantially with the soil substrate. Rodents are hypothesized to act as a reservoir of coccidioidomycosis, a mediator of soil properties, and a disseminator of fungal spores. Rodent distributions are poorly mapped for the study area. We build automated multi-linear regression models and decision tree models for ten rodent species using rodent trapping data from the Organ Pipe Cactus National Monument (ORPI) in southwest Arizona with a combination of surface temperature, a vegetation index and its texture, and a suite of topographic rasters. Surface temperature, derived from Landsat TM thermal images, is the most widely selected predictive variable in both automated methods. Construction-related soil disturbance (e.g. road construction, trenching, land stripping, and earthmoving) is a significant source of fugitive dust, which decreases air quality and may carry soil pathogens. Annual differencing of Landsat Thematic Mapper (TM) mid-infrared images is used to create change images, and thresholded change areas are associated with coordinates of local dust inspections. The output metric identifies source areas of soil disturbance, and it estimates the annual amount of dust-producing surface area for eastern Pima County spanning 1994 through 2009. Spatially explicit construction-related soil disturbance and rodent abundance data are compared with coccidioidomycosis

  9. The Verdesca landslide in the Agri Valley (Basilicata, southern Italy): a new geological and geomorphological framework

    NASA Astrophysics Data System (ADS)

    Gueguen, E.; Bentivenga, M.; Colaiacovo, R.; Margiotta, S.; Summa, V.; Adurno, I.

    2015-11-01

    A landslide, to the west of Montemurro (a small village in southern Italy), has recently caused damage to buildings and other infrastructure in an urbanized area; as a result the development of new economic activities has been prohibited. The landslide phenomenon started in the last century and has been studied since the 1990s using classical geotechnical methods; however the sliding body continues to move. This paper presents the results of a study carried out using field surveys, geognostic investigations and TDR (time domain reflectometry) measurements in order to reconstruct the stratigraphy of the sediments involved and to further understand the geological and geomorphological context of the slope. This study is part of a larger multidisciplinary project, the results of which will also be presented in this paper. The landslide (rotational slide in the upper sector, developing into a translational slide in the lower part) affects Quaternary continental clastic deposits resting on a bedrock formed by Tertiary siliciclastic sediments of the Gorgoglione Flysch. TDR measurements did not show any significant movement during the period monitored (January 2013-January 2014). Slip zone geometries were hypothesized using inclinometric measurements taken from previous studies, stratigraphic data and geomorphological interpretations of topographic scarps. Feedback from monitoring will confirm this hypothesis.

  10. The Verdesca landslide in the Agri Valley (Basilicata, southern Italy): a new geological and geomorphological framework

    NASA Astrophysics Data System (ADS)

    Gueguen, E.; Bentivenga, M.; Colaiacovo, R.; Margiotta, S.; Summa, V.; Adurno, I.

    2015-03-01

    A landslide, to the west of Montemurro (a small village in Southern Italy), has recently caused damage to buildings and other infrastructures in an urbanized area, as a result the development of new economic activities has been prohibited. The landslide was discovered in the last century and has been studied since the 1990's using classical geotechnical methods, but the sliding body continues to move. In this paper, we will present the results of a study carried out using field surveys, geognostic investigations and TDR (Time Domain Reflectometry) measurements in order to reconstruct the stratigraphy of the sediments involved and to further understand the geological and geomorphological context of the slope. This study is part of a larger multidisciplinary project of which the results will also be presented in this paper. The landslide (rotational slide in the upper sector, developing into a translational slide in the lower part) affects Quaternary continental clastic deposits resting on a bedrock formed by Tertiary siliciclastic sediments of the Gorgoglione Flysch. TDR measurements did not show any significant movement during the period monitored (January 2013-January 2014). Slip zone geometries were hypothesized using inclinometric measurements taken from previous studies, stratigraphic data and geomorphological interpretations of topographic scarps. Feedback from monitoring will confirm this hypothesis.

  11. Paleoclimate of the Southern San Joaquin Valley, CA: Research Participation Opportunities for Improving Minority Participation and Achievement in the Geosciences

    NASA Astrophysics Data System (ADS)

    Baron, D.; Negrini, R.; Palacios-Fest, M. R.

    2004-12-01

    Numerous studies have shown that one of the best ways to draw students into geoscience programs is to expose them and their teachers to research projects designed to investigate issues relevant to their lives and communities. To be most effective, involvement in these projects should begin at the pre-college level and continue throughout their college career. Recognizing the importance of genuine research experiences, the Department of Geology at California State University, Bakersfield (CSUB), with support from the National Science Foundation's Opportunities for Enhancing Diversity in the Geosciences program, provides research participation opportunities for teachers and students from the Bakersfield City School District and the Kern High School District. Both districts have a high percentage of low-income and minority students that normally would not consider a degree or career in the geosciences. The project centers around a four-week summer research program and follow-up activities during the school year. The research investigates the climate history of the southern San Joaquin Valley as well as the frequency of flooding in the valley. Many teachers and students are familiar with periodic flooding from personal experience and are aware of the larger issue of climate change in the past and present from news reports. Thus, they can directly relate to the relevance of the research. The project draws on the faculty's expertise in paleoclimatology and geochemistry and takes advantage of CSUB's existing research facilities. Sediments in the dry lake basins of Buena Vista Lake and Kern Lake preserve a record of the regional climate history and flooding of the Kern River and its tributaries. In the first year of the project, 6 teachers and 10 high school students worked with CSUB faculty and students. Three cores from the lake basins were collected. The cores were analyzed using established geophysical, geochemical, lithological, and micropaleontological techniques

  12. Paleogeodesy of the Southern Santa Cruz Mountains Frontal Thrusts, Silicon Valley, CA

    NASA Astrophysics Data System (ADS)

    Aron, F.; Johnstone, S. A.; Mavrommatis, A. P.; Sare, R.; Hilley, G. E.

    2015-12-01

    We present a method to infer long-term fault slip rate distributions using topography by coupling a three-dimensional elastic boundary element model with a geomorphic incision rule. In particular, we used a 10-m-resolution digital elevation model (DEM) to calculate channel steepness (ksn) throughout the actively deforming southern Santa Cruz Mountains in Central California. We then used these values with a power-law incision rule and the Poly3D code to estimate slip rates over seismogenic, kilometer-scale thrust faults accommodating differential uplift of the relief throughout geologic time. Implicit in such an analysis is the assumption that the topographic surface remains unchanged over time as rock is uplifted by slip on the underlying structures. The fault geometries within the area are defined based on surface mapping, as well as active and passive geophysical imaging. Fault elements are assumed to be traction-free in shear (i.e., frictionless), while opening along them is prohibited. The free parameters in the inversion include the components of the remote strain-rate tensor (ɛij) and the bedrock resistance to channel incision (K), which is allowed to vary according to the mapped distribution of geologic units exposed at the surface. The nonlinear components of the geomorphic model required the use of a Markov chain Monte Carlo method, which simulated the posterior density of the components of the remote strain-rate tensor and values of K for the different mapped geologic units. Interestingly, posterior probability distributions of ɛij and K fall well within the broad range of reported values, suggesting that the joint use of elastic boundary element and geomorphic models may have utility in estimating long-term fault slip-rate distributions. Given an adequate DEM, geologic mapping, and fault models, the proposed paleogeodetic method could be applied to other crustal faults with geological and morphological expressions of long-term uplift.

  13. A record of large earthquakes during the past two millennia on the southern Green Valley Fault, California

    USGS Publications Warehouse

    Lienkaemper, James J.; Baldwin, John N.; Turner, Robert; Sickler, Robert R.; Brown, Johnathan

    2013-01-01

    We document evidence for surface-rupturing earthquakes (events) at two trench sites on the southern Green Valley fault, California (SGVF). The 75-80-km long dextral SGVF creeps ~1-4 mm/yr. We identify stratigraphic horizons disrupted by upward-flowering shears and in-filled fissures unlikely to have formed from creep alone. The Mason Rd site exhibits four events from ~1013 CE to the Present. The Lopes Ranch site (LR, 12 km to the south) exhibits three events from 18 BCE to Present including the most recent event (MRE), 1610 ±52 yr CE (1σ) and a two-event interval (18 BCE-238 CE) isolated by a millennium of low deposition. Using Oxcal to model the timing of the 4-event earthquake sequence from radiocarbon data and the LR MRE yields a mean recurrence interval (RI or μ) of 199 ±82 yr (1σ) and ±35 yr (standard error of the mean), the first based on geologic data. The time since the most recent earthquake (open window since MRE) is 402 yr ±52 yr, well past μ~200 yr. The shape of the probability density function (pdf) of the average RI from Oxcal resembles a Brownian Passage Time (BPT) pdf (i.e., rather than normal) that permits rarer longer ruptures potentially involving the Berryessa and Hunting Creek sections of the northernmost GVF. The model coefficient of variation (cv, σ/μ) is 0.41, but a larger value (cv ~0.6) fits better when using BPT. A BPT pdf with μ of 250 yr and cv of 0.6 yields 30-yr rupture probabilities of 20-25% versus a Poisson probability of 11-17%.

  14. Comparison of peak discharges among sites with and without valley fills for the July 8-9, 2001 flood in the headwaters of Clear Fork, Coal River basin, mountaintop coal-mining region, southern West Virginia

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Brogan, Freddie D.

    2003-01-01

    The effects of mountaintop-removal mining practices on the peak discharges of streams were investigated in six small drainage basins within a 7-square-mile area in southern West Virginia. Two of the small basins had reclaimed valley fills, one basin had reclaimed and unreclaimed valley fills, and three basins did not have valley fills. Indirect measurements of peak discharge for the flood of July 8-9, 2001, were made at six sites on streams draining the small basins. The sites without valley fills had peak discharges with 10- to 25-year recurrence intervals, indicating that rainfall intensities and totals varied among the study basins. The flood-recurrence intervals for the three basins with valley fills were determined as though the peak discharges were those from rural streams without the influence of valley fills, and ranged from less than 2 years to more than 100 years.

  15. Crustal Spreading in Southern California: The Imperial Valley and the Gulf of California formed by the rifting apart of a continental plate.

    PubMed

    Elders, W A; Rex, R W; Robinson, P T; Biehler, S; Meidav, T

    1972-10-01

    The current excitement among geologists and geophysicists stemming from the "new global tectonics" has led to a widespread, speculative reinterpretation of continental geology. The Gulf of California and its continuation into the Imperial Valley provide an excellent opportunity for studying the border zone between the North American and Pacific plates, and an interface of continental and oceanic tectonics. The Salton trough, the landward extension of the gulf, is a broad structural depression, comparable in size with the deeper marine basins of the southern part of the gulf, but here partially filled with sediments deposited by the Colorado River. PMID:17754729

  16. Crustal Spreading in Southern California: The Imperial Valley and the Gulf of California formed by the rifting apart of a continental plate.

    PubMed

    Elders, W A; Rex, R W; Robinson, P T; Biehler, S; Meidav, T

    1972-10-01

    The current excitement among geologists and geophysicists stemming from the "new global tectonics" has led to a widespread, speculative reinterpretation of continental geology. The Gulf of California and its continuation into the Imperial Valley provide an excellent opportunity for studying the border zone between the North American and Pacific plates, and an interface of continental and oceanic tectonics. The Salton trough, the landward extension of the gulf, is a broad structural depression, comparable in size with the deeper marine basins of the southern part of the gulf, but here partially filled with sediments deposited by the Colorado River.

  17. Ground-water outflow, San Timoteo-Smiley Heights area, upper Santa Ana Valley, Southern California, 1927 through 1968

    USGS Publications Warehouse

    Dutcher, L.C.; Fenzel, F.W.

    1972-01-01

    The San Timoteo-Smiley Heights area is in the upper Santa Ana Valley, San Bernardino and Riverside Counties, Calif., where the Yucaipa and San Timoteo-Beaumont ground-water basins border Bunker .Hill basin on the south between the San Jacinto and San Andreas faults. The area is broken by numerous faults, the topography is rough, and in a large part of the area few wells had been drilled prior to 196S. The alluvial deposits, which constitute the aquifers in the area, range in thickness from 0 where they lap onto exposed bedrock hills to about 1,000 feet. Beneath the southern part of the area near the San Jacinto fault the total thickness of alluvial and lacustrine deposits may be as much as 6,000 feet. The purpose of this study was to estimate ground-water outflow by an indirect method not involving balancing of the hydrologic budget. For this purpose it was necessary to estimate the permeability of the aquifer materials, the average annual hydraulic gradient, and the cross-sectional area through which the flow occurs; these values were estimated for five segments along a line of section between the San Jacinto fault and Crafton Hills. To provide data for the outflow estimates, several miles of reflection and refraction seismic traverses were made along and across the outflow section. Nineteen deep and shallow test holes were drilled; one of the deep test holes and several existing wells were pumped to obtain data on aquifer permeability. The estimated average permeabilities of the aquifer materials range from 5 gallons per day per square foot for the lower part of the San Timoteo beds of Frick (1921) and 40 gallons per day per square foot for the older alluvium to 220 gallons per day per square foot for the upper part of the San Timoteo beds. The estimated outflow in 1927 was 8,150 acre-feet. By 1967 the estimated total outflow was 5,350 acre-feet, a reduction of approximately 34 percent. During the 12-year period 1956 through 1967, however, the annual outflow

  18. Status of groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units, 2005-08: California GAMA Priority Basin Project

    USGS Publications Warehouse

    Bennett, George L.; Fram, Miranda S.; Belitz, Kenneth

    2011-01-01

    Groundwater quality in the Southern, Middle, and Northern Sacramento Valley study units was investigated as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study units are located in California's Central Valley and include parts of Butte, Colusa, Glenn, Placer, Sacramento, Shasta, Solano, Sutter, Tehama, Yolo, and Yuba Counties. The GAMA Priority Basin Project is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory. The three study units were designated to provide spatially-unbiased assessments of the quality of untreated groundwater in three parts of the Central Valley hydrogeologic province, as well as to provide a statistically consistent basis for comparing water quality regionally and statewide. Samples were collected in 2005 (Southern Sacramento Valley), 2006 (Middle Sacramento Valley), and 2007-08 (Northern Sacramento Valley). The GAMA studies in the Southern, Middle, and Northern Sacramento Valley were designed to provide statistically robust assessments of the quality of untreated groundwater in the primary aquifer systems that are used for drinking-water supply. The assessments are based on water-quality data collected by the USGS from 235 wells in the three study units in 2005-08, and water-quality data from the California Department of Public Health (CDPH) database. The primary aquifer systems (hereinafter, referred to as primary aquifers) assessed in this study are defined by the depth intervals of the wells in the CDPH database for each study unit. The quality of groundwater in shallow or deep water-bearing zones may differ from quality of groundwater in the primary aquifers; shallow groundwater may be more vulnerable to contamination from the surface. The status of the current quality of the groundwater resource was assessed by using data from samples analyzed for volatile organic

  19. Prediction, Assessment of the Rift Valley Fever Activity in East and Southern Africa 2006–2008 and Possible Vector Control Strategies

    PubMed Central

    Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, Seth C.; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W.; Breiman, Robert F.; Chretien, Jean-Paul; Tucker, Compton J.; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B.; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M.; Reynes, Jean-Marc; Swanepoel, Robert

    2010-01-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2–4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future. PMID:20682905

  20. Prediction, assessment of the Rift Valley fever activity in East and Southern Africa 2006-2008 and possible vector control strategies.

    PubMed

    Anyamba, Assaf; Linthicum, Kenneth J; Small, Jennifer; Britch, Seth C; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W; Breiman, Robert F; Chretien, Jean-Paul; Tucker, Compton J; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M; Reynes, Jean-Marc; Swanepoel, Robert

    2010-08-01

    Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2-4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future. PMID:20682905

  1. Paleosols in low-order streams and valley heads in the Araucaria Plateau - Record of continental environmental conditions in southern Brazil at the end of MIS 3

    NASA Astrophysics Data System (ADS)

    Paisani, Julio Cesar; Pontelli, Marga Eliz; Osterrieth, Margarita Luisa; Paisani, Sani Daniela Lopes; Fachin, Andressa; Guerra, Simone; Oliveira, Leandro

    2014-10-01

    The Araucaria Plateau is a geomorphological unit that occupies approximately three-quarters of the terrain in the southern region of Brazil. The plateau displays different altitudinal levels (600 to <1400 m a.s.l.) that are locally recognized as remnants of planed surfaces (S8-S1). These surfaces are maintained by basic (S3-S8) and acidic (S1 and S2) volcanic flows from the Neocretaceous period of the Paraná Basin. The largest extent of this plateau is located in a humid subtropical climate zone. Colluvial, colluvial-alluvial, alluvial sediments and paleosols (Ab diagnostic horizons) occur predominantly in S2. The paleosols are located in low-hierarchical-order fossil valleys (first- to fourth-order in Strahler's stream classification) and valley heads, which are referred to as paleovalleys in this paper. We employed these paleosols as stratigraphic level markers of the pedogenesis of the regional Upper Quaternary and propose their importance as records of the paleoenvironmental conditions of the Araucaria Plateau in areas above 1200 m a.s.l. These paleosols were dated by 14C and show ages between 23.8 ± 0.05 kyr BP (28.06-29.08 kyr cal. BP) and 41.16 ± 0.48 kyr BP (44.13-45.58 kyr cal. BP). The calibrated ages are related to Marine Isotope Stage 3 (MIS 3), in which the last period of global warming occurred (approximately 60-25 kyr cal. BP). We integrated the morphological, pedogeochemical, clay fraction mineralogy, micromorphological and δC-13 analyses of five paleosols from S2 to verify the paleoenvironmental conditions of the Araucaria Plateau and its correspondence with the paleoclimatic phenomena that were identified on a global scale during MIS 3 in the Southern Hemisphere. We obtained the following conclusions: a) the properties of paleosols reflect pedological processes that are adjusted to the paleoenvironmental conditions at the end of MIS 3 and the transition to MIS 2 (Last Glacial Maximum); b) aplasmogenic partial acidolysis was the predominant

  2. Predictors of mistimed, and unwanted pregnancies among women of childbearing age in Rufiji, Kilombero, and Ulanga districts of Tanzania

    PubMed Central

    2014-01-01

    Background While unintended pregnancies pose a serious threat to the health and well-being of families globally, characteristics of Tanzanian women who conceive unintentionally are rarely documented. This analysis identifies factors associated with unintended pregnancies—both mistimed and unwanted—in three rural districts of Tanzania. Methods A cross-sectional survey of 2,183 random households was conducted in three Tanzanian districts of Rufiji, Kilombero, and Ulanga in 2011 to assess women’s health behavior and service utilization patterns. These households produced 3,127 women age 15+ years from which 2,199 gravid women aged 15–49 were selected for the current analysis. Unintended pregnancies were identified as either mistimed (wanted later) or unwanted (not wanted at all). Correlates of mistimed, and unwanted pregnancies were identified through Chi-squared tests to assess associations and multinomial logistic regression for multivariate analysis. Results Mean age of the participants was 32.1 years. While 54.1% of the participants reported that their most recent pregnancy was intended, 32.5% indicated their most recent pregnancy as mistimed and 13.4% as unwanted. Multivariate analysis revealed that young age (<20 years), and single marital status were significant predictors of both mistimed and unwanted pregnancies. Lack of inter-partner communication about family planning increased the risk of mistimed pregnancy significantly, and multi-gravidity was shown to significantly increase the risk of unwanted pregnancy. Conclusions About one half of women in Rufiji, Kilombero, and Ulanga districts of Tanzania conceive unintentionally. Women, especially the most vulnerable should be empowered to avoid pregnancy at their own will and discretion. PMID:25102924

  3. Greenhouse gas sources in the southern San Joaquin Valley of California derived from Positive Matrix Factorization of CalNex 2010 observations

    NASA Astrophysics Data System (ADS)

    Guha, A.; Gentner, D. R.; Weber, R.; Baer, D. S.; Gardner, A.; Provencal, R. A.; Goldstein, A. H.

    2012-12-01

    Quantifying the contributions of methane (CH4) and nitrous oxide (N2O) emission from sources in the southern San Joaquin valley is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law (California Global Warming Solutions Act 2006) implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The "bottom-up" emission factors for CH4 and N2O have large uncertainties and there is a lack of adequate "top-down" measurements to characterize emission rates from sources. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agriculture and industry intensive region with large concentration of dairies, refineries and active oil fields which are known CH4 sources while agricultural soil management and vehicular combustion are known sources of N2O. In summer of 2010, GHG sources in the southern San Joaquin valley were investigated as part of the CalNex (California at the Nexus of Air Quality and Climate Change) campaign. Measurements of GHG gases (CO2, CH4, and N2O) and the combustion tracer CO were performed at the Bakersfield super-site over a period of six weeks using fast response lasers based on cavity enhanced absorption spectroscopy (LGR Inc. CA). Coincident measurements of hundreds of volatile organic compounds (VOCs) served as anthropogenic and biogenic tracers of the GHG sources at local and regional levels. We present the results of Positive Matrix Factorization (PMF) analysis applied to the GHGs, CO, and 60 VOCs to define dominant source emission profiles. Seven source factors were identified and used to attribute the contribution of regional sources to enhancements above the background. Dairy operations were found to be the largest CH4 source in the region with approximately 80% of the regional emissions attributed to the 'dairy' factor. Factors dominated

  4. Style of deformation along the Death Valley-Furnace Creek fault zone and other faults in the southern Walker Lane, Nevada and California

    SciTech Connect

    Noller, J.S. ); Reheis, M.C. )

    1993-04-01

    Quaternary normal and right-lateral faults and associated lineaments in the southern part of the Walker Lane are anomalous with respect to the north-striking normal faults in most of the central Great Basin. The authors identify and characterize many faults and lineaments that were previously unmapped, with the exception of faults in the Death Valley-Furnace Creek fault zone (DVFCFZ) and some faults in and near the Nevada Test Site. Faults and associated lineaments in deposits of late Cenozoic age are distinguished on the basis of age of most recent activity and orientation, and are grouped into two domains. One domain is characterized by northwest-striking faults and lineaments and associated north-striking en echelon structures within the DVFCFZ and the Pahrump fault zone; the other domain is characterized by north- to northeast-striking faults and linearments within a broad region east of the DVFCFZ that narrows southward toward the Pahrump fault zone. Preliminary observations of faults and linearments suggest dominantly right-oblique slip in the first domain and dominantly dip-slip in the second domain. The DVFCFZ is a regional right-lateral strike-slip system that shows changes in style of deformation along strike. Numerous normal faults at the northern end of the DVFCFZ in northern fish Lake Valley and the Volcanic Hills form an extensional right step that links the DVFCFZ with northwest-striking right-lateral faults of the northern part of the Walker Lane. South of this extensional step, the DVFCFZ trends southeast along strike-slip faults from central Fish Lake Valley to the latitude of Furnace Creek. From Furnace Creek, the fault zone apparently steps left to the Pahrump fault zone in the area of Ash Meadows where a complex zone of folds and faults of diverse orientation suggest local compression. This stepover coincides with east-northeast-striking faults that appear to be an extension of the left-lateral Rock Valley fault zone.

  5. Interbasin flow in the Great Basin with special reference to the southern Funeral Mountains and the source of Furnace Creek springs, Death Valley, California, U.S.

    USGS Publications Warehouse

    Belcher, W.R.; Bedinger, M.S.; Back, J.T.; Sweetkind, D.S.

    2009-01-01

    Interbasin flow in the Great Basin has been established by scientific studies during the past century. While not occurring uniformly between all basins, its occurrence is common and is a function of the hydraulic gradient between basins and hydraulic conductivity of the intervening rocks. The Furnace Creek springs in Death Valley, California are an example of large volume springs that are widely accepted as being the discharge points of regional interbasin flow. The flow path has been interpreted historically to be through consolidated Paleozoic carbonate rocks in the southern Funeral Mountains. This work reviews the preponderance of evidence supporting the concept of interbasin flow in the Death Valley region and the Great Basin and addresses the conceptual model of pluvial and recent recharge [Nelson, S.T., Anderson, K., Mayo, A.L., 2004. Testing the interbasin flow hypothesis at Death Valley, California. EOS 85, 349; Anderson, K., Nelson, S., Mayo, A., Tingey, D., 2006. Interbasin flow revisited: the contribution of local recharge to high-discharge springs, Death Valley, California. Journal of Hydrology 323, 276-302] as the source of the Furnace Creek springs. We find that there is insufficient modern recharge and insufficient storage potential and permeability within the basin-fill units in the Furnace Creek basin for these to serve as a local aquifer. Further, the lack of high sulfate content in the spring waters argues against significant flow through basin-fill sediments and instead suggests flow through underlying consolidated carbonate rocks. The maximum temperature of the spring discharge appears to require deep circulation through consolidated rocks; the Tertiary basin fill is of insufficient thickness to generate such temperatures as a result of local fluid circulation. Finally, the stable isotope data and chemical mass balance modeling actually support the interbasin flow conceptual model rather than the alternative presented in Nelson et al. [Nelson

  6. Ground-Water Quality Data in the Southern Sacramento Valley, California, 2005 - Results from the California GAMA Program

    USGS Publications Warehouse

    Milby Dawson, Barbara J.; Bennett, George L.; Belitz, Kenneth

    2008-01-01

    Ground-water quality in the approximately 2,100 square-mile Southern Sacramento Valley study unit (SSACV) was investigated from March to June 2005 as part of the Statewide Basin Assessment Project of Ground-Water Ambient Monitoring and Assessment (GAMA) Program. This study was designed to provide a spatially unbiased assessment of raw ground-water quality within SSACV, as well as a statistically consistent basis for comparing water quality throughout California. Samples were collected from 83 wells in Placer, Sacramento, Solano, Sutter, and Yolo Counties. Sixty-seven of the wells were selected using a randomized grid-based method to provide statistical representation of the study area. Sixteen of the wells were sampled to evaluate changes in water chemistry along ground-water flow paths. Four additional samples were collected at one of the wells to evaluate water-quality changes with depth. The GAMA Statewide Basin Assessment project was developed in response to the Ground-Water Quality Monitoring Act of 2001 and is being conducted by the California State Water Resources Control Board (SWRCB) in collaboration with the U.S. Geological Survey (USGS) and the Lawrence Livermore National Laboratory (LLNL). The ground-water samples were analyzed for a large number of man-made organic constituents (volatile organic compounds [VOCs], pesticides and pesticide degradates, pharmaceutical compounds, and wastewater-indicator constituents), constituents of special interest (perchlorate, N-nitrosodimethylamine [NDMA], and 1,2,3-trichloropropane [1,2,3-TCP]), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, and carbon-14, and stable isotopes of hydrogen, oxygen, and carbon), and dissolved noble gases also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blanks, replicates, matrix spikes

  7. Precipitation of lead-zinc ores in the Mississippi Valley-type deposit at Treves, Cevennes region of southern France

    USGS Publications Warehouse

    Leach, D.; Macquar, J.-C.; Lagneau, V.; Leventhal, J.; Emsbo, P.; Premo, W.

    2006-01-01

    The Trèves zinc–lead deposit is one of several Mississippi Valley-type (MVT) deposits in the Cévennes region of southern France. Fluid inclusion studies show that the ore was deposited at temperatures between approximately 80 and 150°C from a brine that derived its salinity mainly from the evaporation of seawater past halite saturation. Lead isotope studies suggest that the metals were extracted from local basement rocks. Sulfur isotope data and studies of organic matter indicate that the reduced sulfur in the ores was derived from the reduction of Mesozoic marine sulfate by thermochemical sulfate reduction or bacterially mediated processes at a different time or place from ore deposition. The large range of δ34S values determined for the minerals in the deposit (12.2–19.2‰ for barite, 3.8–13.8‰ for sphalerite and galena, and 8.7 to −21.2‰ for pyrite), are best explained by the mixing of fluids containing different sources of sulfur. Geochemical reaction path calculations, based on quantitative fluid inclusion data and constrained by field observations, were used to evaluate possible precipitation mechanisms. The most important precipitation mechanism was probably the mixing of fluids containing different metal and reduced sulfur contents. Cooling, dilution, and changes in pH of the ore fluid probably played a minor role in the precipitation of ores. The optimum results that produced the most metal sulfide deposition with the least amount of fluid was the mixing of a fluid containing low amounts of reduced sulfur with a sulfur-rich, metal poor fluid. In this scenario, large amounts of sphalerite and galena are precipitated, together with smaller quantities of pyrite precipitated and dolomite dissolved. The relative amounts of metal precipitated and dolomite dissolved in this scenario agree with field observations that show only minor dolomite dissolution during ore deposition. The modeling results demonstrate the important control of the reduced

  8. Study of LANDSAT-D thematic mapper performance as applied to hydrocarbon exploration. [Southern Ontario, Lawton, Oklahoma; Owl Creek, Wyoming; Washington, D.C.; and Death Valley California

    NASA Technical Reports Server (NTRS)

    Everett, J. R. (Principal Investigator)

    1983-01-01

    Improved delineation of known oil and gas fields in southern Ontario and a spectacularly high amount of structural information on the Owl Creek, Wyoming scene were obtained from analysis of TM data. The use of hue, saturation, and value image processing techniques on a Death Valley, California scene permitted direct comparison of TM processed imagery with existing 1:250,000 scale geological maps of the area and revealed small outcrops of Tertiary volcanic material overlying Paleozoic sections. Analysis of TM data over Lawton, Oklahoma suggests that the reducing chemical environment associated with hydrocarbon seepage change ferric iron to soluble ferrous iron, allowing it to be leached. Results of the band selection algorithm show a suprising consistency, with the 1,4,5 combination selected as optimal in most cases.

  9. Sequence diversity of the merozoite surface protein 1 of Plasmodium falciparum in clinical isolates from the Kilombero District, Tanzania.

    PubMed

    Jiang, G; Daubenberger, C; Huber, W; Matile, H; Tanner, M; Pluschke, G

    2000-01-01

    Merozoite surface protein 1 of Plasmodium falciparum (PfMSP-1) is regarded as a key candidate antigen for malaria vaccine development. It exhibits significant antigenic polymorphism and has been divided into 17 building blocks based on the analysis of sequence diversity. Differences in the antigenic composition of PfMSP-1 in local P. falciparum populations may result in differences in the efficacy of vaccines, which contain sequences of particular allelic variant(s) of PfMSP-1. To contribute to the required knowledge of genetic diversity of malaria parasites in geographically diverse regions, we have used the polymerase chain reaction (PCR) to analyze the sequence diversity of blocks 1-4 of PfMSP-1 in disease isolates from the Kilombero District in Tanzania. In the semi-conserved block 1, in which dimorphic amino acid variances have been described at three positions, we found three of the five previously described combinations of these three pairs of amino acids. In addition one combination was found, which has not been reported before in parasite isolates from different locations worldwide. Of the two sequence variants, which were dominating, one (S44-Q47-V52) corresponded to the 83.1 sequence incorporated into the SPf66 malaria peptide vaccine, while the other one (G44-H47-I52) differed from the previous in all three dimorphic amino acids. The partial protection observed in a phase III SPf66 trial conducted in the Kilombero District in children aged 1-5, thus does not seem to be associated with a clear dominance of favourable variants of block 1 of PfMSP-1 in this area. All three different principle types of block 2, the major polymorphic region of PfMSP-1, were found in the Tanzanian isolates. Most of the sequences contained K1-type tripeptide repeats, but clones with MAD20-type repeats or no repetitive sequence (RO33-type block 2) were also present. K1- and MAD20-type tripeptide repeat motifs were never mixed within one parasite clone. In one sequence a

  10. A regional record of expanded Holocene wetlands and prehistoric human occupation from paleowetland deposits of the western Yarlung Tsangpo valley, southern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Hudson, Adam M.; Olsen, John W.; Quade, Jay; Lei, Guoliang; Huth, Tyler E.; Zhang, Hucai

    2016-07-01

    The Asian Monsoon, which brings ∼80% of annual precipitation to much of the Tibetan Plateau, provides runoff to major rivers across the Asian continent. Paleoclimate records indicate summer insolation and North Atlantic paleotemperature changes forced variations in monsoon rainfall through the Holocene, resulting in hydrologic and ecologic changes in plateau watersheds. We present a record of Holocene hydrologic variability in the Yarlung Tsangpo (YT) valley of the southern Tibetan Plateau, based on sedimentology and 14C dating of organic-rich 'black mats' in paleowetlands deposits, that shows changes in wetlands extent in response to changing monsoon intensity. Four sedimentary units indicate decreasing monsoon intensity since 10.4 ka BP. Wet conditions occurred at ∼10.4 ka BP, ∼9.6 ka BP and ∼7.9-4.8 ka BP, with similar-to-modern conditions from ∼4.6-2.0 ka BP, and drier-than-modern conditions from ∼2.0 ka BP to present. Wetland changes correlate with monsoon intensity changes identified in nearby records, with weak monsoon intervals corresponding to desiccation and erosion of wetlands. Dating of in situ ceramic and microlithic artifacts within the wetlands indicates Epipaleolithic human occupation of the YT valley after 6.6 ka BP, supporting evidence for widespread colonization of the Tibetan Plateau in the early and mid-Holocene during warm, wet post-glacial conditions.

  11. Large Alluvial Fans in the Araba Valley (Jordan) as a Record of Tectonic Deformation of the Southern Dead Sea Fault and Regional Paleoclimates

    NASA Astrophysics Data System (ADS)

    Le Beon, M.; Klinger, Y.; Al-Qaryouti, M.; Meriaux, A.; Finkel, R. C.; Mayyas, O.; Ryerson, F. J.; Tapponnier, P.

    2007-12-01

    The Dead Sea fault is the 1000 km-long strike-slip fault that accommodates northward motion of Arabia relative to Sinai at a rate of about 5 mm/yr. This study focuses on the southern segment of this fault, the Wadi Araba fault. From the Dead Sea basin to the Gulf of Aqaba, the fault runs along an axial valley, about 20 km wide and 150 km long, bounded to the east by the Jordanian Plateau, reaching 1500 m in elevation and to the west by the Negev Plateau, lower in elevation (500-700 m). The Araba valley is floored with Plio-Quaternary deposits and in particular with large alluvial fans that are cut by the fault and offset relative to their feeding channel. We mapped the valley floor in details and dated some of these fans first to assess their lateral offset and further constrain the slip rate on the fault, and secondly to try to correlate alluvial fan aggradation periods in this arid/semi-arid environment to paleoclimatic variations at the regional and global scales. To identify the possible sources of the large alluvial fans, we analyzed the drainage network and the catchment basins on the valley rims based on SRTM3 topography. Previous study suggested that these fans were Pliocene and underwent offsets of 15 to 30 km. Ages as young as 50 to 350 kyr derived from 10Be exposure dating of 33 samples from the surface of some of these fans indicate that such offsets are very unlikely. Actual offsets have to be smaller. Preliminary reconstructions suggest offsets of 700-1300 m and 1600-2000 m for fans dated at 160 +/- 20 kyr and 330 +/- 22 kyr respectively, and offsets of 2.5-3.5 and 4.4-5.4 km for older fans that have not been dated yet. Consistent ages at different sites suggest simultaneous fan emplacement controlled by some external controlling factor such as climate variations. The correlation between these aggradation episodes and paleoclimatic variations would allow us to draw hypotheses on the age of these older surfaces. These preliminary results provide new

  12. Status and understanding of groundwater quality in the two southern San Joaquin Valley study units, 2005-2006 - California GAMA Priority Basin Project

    USGS Publications Warehouse

    Burton, Carmen A.; Shelton, Jennifer L.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the southern San Joaquin Valley was investigated from October 2005 through March 2006 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. There are two study units located in the southern San Joaquin Valley: the Southeast San Joaquin Valley (SESJ) study unit and the Kern County Subbasin (KERN) study unit. The GAMA Priority Basin Project in the SESJ and KERN study units was designed to provide a statistically unbiased, spatially distributed assessment of untreated groundwater quality within the primary aquifers. The status assessment is based on water-quality and ancillary data collected in 2005 and 2006 by the USGS from 130 wells on a spatially distributed grid, and water-quality data from the California Department of Public Health (CDPH) database. Data was collected from an additional 19 wells for the understanding assessment. The aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the SESJ and KERN study units. The status assessment of groundwater quality used data from samples analyzed for anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources within the primary aquifers in the SESJ and KERN study units, not the quality of drinking water delivered to consumers. Although the status assessment applies to untreated groundwater, Federal and California regulatory and non-regulatory water-quality benchmarks that apply to drinking water are used

  13. Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Caggiano, R.; Trippetta, S.; Sabia, S.

    2015-02-01

    The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn) were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy). The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy), about 30 km away from the study area along the north direction. The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC) ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6-12-month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6-month and 12-month-exposed samples. Moreover, principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA) plant emissions and the African dust long-range transport were also identified.

  14. Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

    NASA Astrophysics Data System (ADS)

    Caggiano, R.; Trippetta, S.; Sabia, S.

    2014-10-01

    The atmospheric concentrations of 17 trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, S, Ti and Zn) were measured by means of the "lichen-bag" technique in the Agri Valley (southern Italy). The lichen samples were collected from an unpolluted site located in Rifreddo forest (southern Italy). The bags were exposed to ambient air for 6 and 12 months. The exposed-to-control (EC) ratio values highlighted that the used lichen species were suitable for biomonitoring investigations. The results showed that the concentrations of almost all the examined trace elements increased with respect to the control after 6-12 month exposures. Furthermore, Ca, Al, Fe, K, Mg and S were the most abundant trace elements both in the 6 and 12 month-exposed samples. Moreover, principal component analysis (PCA) results highlighted that the major sources of the measured atmospheric trace elements were related both to anthropogenic contributions due to traffic, combustion processes, agricultural practices, construction and quarrying activities, and to natural contributions mainly represented by the re-suspension of local soil and road dusts. In addition, the contribution both of secondary atmospheric reactions involving Centro Olio Val d'Agri (COVA) plant emissions and the African dust long-range transport were also identified.

  15. Seismic Structure of the San Fernando and Antelope Valleys, Southern California: Results From LARSE II Refraction, Industry Reflection, and Oil-Test Well Data

    NASA Astrophysics Data System (ADS)

    Fuis, G. S.; Thygesen, K.; Lim, K.; Okaya, D. A.; Baher, S.; Simila, G.; Murphy, J. M.; Ryberg, T.; Langenheim, V. E.

    2003-12-01

    The second phase of the Los Angeles Region Seismic Experiment (LARSE II) recorded refraction and low-fold reflection data from the Santa Monica Mts. to the southern Sierra Nevada, in southern California. The LARSE II corridor crossed two sedimentary basins, underlying the San Fernando and Antelope Valleys, for which we have both industry reflection and oil-test well data to aid in interpretation of geologic structure. In the San Fernando Valley (SFV), refraction modeling of the main line and three cross lines reveal five primary layers. Layer 1 (1.3 km/s), up to 0.1 km thick, represents unsaturated, unconsolidated Quaternary (Q) sediments, and Layer 2 (1.8-2.3 km/s), up to 0.4 km thick, represents saturated, unconsolidated Q sediments and weathered Tertiary (T) sedimentary rocks. Using industry reflection sections and oil-test well data, we observe the following for deeper layers: South of the Northridge Hills fault (NHF), located in the northern SFV, Layer 3 (2.3-3.2 km/s), up to 1.6 km thick, corresponds chiefly to reflective T rocks, including Modelo through Saugus Formations, and Layer 4 (3.6-4.8 km/s), up to 2.2 km thick, corresponds chiefly to non-reflective Topanga Formation and older rocks. North of the NHF, the relationship of velocity layering to stratigraphy becomes more complex, and velocities appear to increase somewhat throughout the stratigraphic section. Layer 5 (5.0-6.0 km/s) is interpreted as basement rocks and may include Mesozoic igneous and metamorphic rocks. The top of layer 5 is deepest (4 km) just north of the surface trace of the NHF. Layers 3-5 thicken markedly northward in the southern SFV, and the boundary between layers 3 and 4 is offset, up to the north, along the north-dipping NHF. In the Antelope Valley (AV), located in the western Mojave Desert, refraction modeling has identified four basic layers. Preliminary interpretations are as follows: Layer 1 (0.1 km/s or less), up to 0.2 km thick, is unsaturated, unconsolidated Q sediments

  16. Forest adjacent households' voices on their perceptions and adaptation strategies to climate change in Kilombero District, Tanzania.

    PubMed

    Balama, Chelestino; Augustino, Suzana; Eriksen, Siri; Makonda, Fortunatus B S

    2016-01-01

    Climate change is a global and local challenge to both sustainable livelihoods and economic development. Tanzania as other countries of the world has been affected. Several studies have been conducted on farmers' perceptions and adaptation to climate change in the country, but little attention has been devoted to forest adjacent households in humid areas. This study assessed this gap through assessing forest adjacent households' voices on perceptions and adaptation strategies to climate change in Kilombero District, Tanzania. Data collection involved key informant interviews, focus group discussions and household questionnaires. Results showed that the majority of households perceived changed climate in terms of temperature increase, unpredictable rainfall, frequent occurrence of floods, increased dry spells during rainy season coupled with decreased water sources and emergence of new pests and diseases. The perceived change in climate has impacted agriculture productivity as the main livelihood source. Different coping and adaptation strategies are employed. These are; crop diversification, changing cropping calendar, adopting modern farming technologies, and increasing reliance on non-timber forest products. These strategies were positively and significantly influenced by socio-economic factors including household size, residence period, land ownership and household income. The study concludes that, there are changes in climatic conditions; and to respond to these climatic changes, forest adjacent households have developed numerous coping and adaptation strategies, which were positively and significantly influenced by some socio-economic factors. The study calls for actual implementation of local climate change policies and strategies in order to enhance adaptive capacity at household level. PMID:27390633

  17. Forest adjacent households' voices on their perceptions and adaptation strategies to climate change in Kilombero District, Tanzania.

    PubMed

    Balama, Chelestino; Augustino, Suzana; Eriksen, Siri; Makonda, Fortunatus B S

    2016-01-01

    Climate change is a global and local challenge to both sustainable livelihoods and economic development. Tanzania as other countries of the world has been affected. Several studies have been conducted on farmers' perceptions and adaptation to climate change in the country, but little attention has been devoted to forest adjacent households in humid areas. This study assessed this gap through assessing forest adjacent households' voices on perceptions and adaptation strategies to climate change in Kilombero District, Tanzania. Data collection involved key informant interviews, focus group discussions and household questionnaires. Results showed that the majority of households perceived changed climate in terms of temperature increase, unpredictable rainfall, frequent occurrence of floods, increased dry spells during rainy season coupled with decreased water sources and emergence of new pests and diseases. The perceived change in climate has impacted agriculture productivity as the main livelihood source. Different coping and adaptation strategies are employed. These are; crop diversification, changing cropping calendar, adopting modern farming technologies, and increasing reliance on non-timber forest products. These strategies were positively and significantly influenced by socio-economic factors including household size, residence period, land ownership and household income. The study concludes that, there are changes in climatic conditions; and to respond to these climatic changes, forest adjacent households have developed numerous coping and adaptation strategies, which were positively and significantly influenced by some socio-economic factors. The study calls for actual implementation of local climate change policies and strategies in order to enhance adaptive capacity at household level.

  18. Interpretation of gravity profiles across the northern Oaxaca terrane, its boundaries and the Tehuacán Valley, southern Mexico

    NASA Astrophysics Data System (ADS)

    Campos-Enríquez, J. O.; Alatorre-Zamora, M. A.; Keppie, J. D.; Belmonte-Jiménez, S. I.; Ramón-Márquez, V. M.

    2014-12-01

    A gravity study was conducted across the northern Oaxaca terrane and its bounding faults: the Caltepec and Oaxaca Faults to the west and east, respectively. These faults juxtapose the Oaxaca terrane against the Mixteca and Juarez terranes, respectively. The Oaxaca Fault also forms the eastern boundary of the Cenozoic Tehuacán depression. On the west, at depth, the Tehuacán valley is limited by the normal buried Tehuacán Fault. This gravity study reveals that the Oaxaca Fault system gives rise to a series of east tilted basamental blocks (Oaxaca Complex). The tectonic depression is filled with Phanerozoic rocks and has a deeper depocenter to the west. The gravity data also indicate that on the west, the Oaxaca Complex, the Caltepec and Santa Lucia faults continue northwestwards beneath Phanerozoic rocks. A major E-W to NE-SW discontinuity is inferred to exist between profiles 1 and 2.

  19. Chemical data and variation diagrams of igneous rocks from the Timber Mountain-Oasis Valley Caldera Complex, southern Nevada

    USGS Publications Warehouse

    Quinlivan, W.D.; Byers, F.M.

    1977-01-01

    Silica variation diagrams presented here are based on 162 chemical analyses of tuffs, lavas, and intrusives, representative of volcanic centers of the Timber Mountain-Oasis Valley caldera complex and cogenetic rocks of the Silent Canyon ca1dera. Most of the volcanic units sampled are shown on the U.S. Geological Survey geologic map of the Timber Mountain caldera area (I-891) and are described in U.S. Geological Survey Professional Paper 919. Early effusives of the complex, although slightly altered, are probably chemically, and petrographically, more like the calc-alkalic Fraction Tuff (Miocene) of the northern Nellis Air Force Base Bombing and Gunnery Range to the north, whereas effusives of later Miocene age, such as the Paintbrush and Timber Mountain Tuffs, are alkali-calcic.

  20. Development of an Upper Cambrian rimmed shelf along the Mississippi Valley Graben, Reelfoot Rift, and the southeastern Ozarks, southern Missouri

    SciTech Connect

    Palmer, J.R. . Dept. of Natural Resources)

    1993-03-01

    The paleogeographic distribution of intrashelf basin shales and limestones in the Bonneterre (Dresbachian) and Davis (Franconian) Formations, and associated data, suggests that rimmed shelf conditions separated the central Missouri part of the shelf from the Mississippi Valley Graben (MVG) of the Reelfoot Rift to the southeast. Middle Dresbachian rocks of the intrashelf basin area, predominantly limestones, indicate a discontinuous carbonate shelf rim. The succeeding widespread shales of the Franconian intrashelf basin indicate that a continuous rim had developed. The margin of the shelf rim is preserved in part of the 4,700-ft-thick Upper Cambrian succession along the northwest margin of the Mississippi Valley Graben (MVG) of the Reelfoot Rift. Equivalent rocks within the MVG are dominantly dark shales (1,600+ ft thick). The Amoco Spence test well penetrated the rim succession on the northwest margin of the MVG. At least 11 large-scale transgressive-regressive (T-R) carbonate cycles (120--600 ft thick) have been defined in this well; 7 cycles are equivalent to the Bonneterre and Davis Formations. These latter cycles have shaly limestone, or limestone at the base, and grade upward to dolostone or coarsely crystalline dolostone, which are interpreted to be shallowing-upward, bank margin-peritidal carbonates. Northwest of the rim margin and on the southeast side of the St. Francois Mountains, rocks equivalent to the rim succession consist of a series of ramp to platform cycles made up of dolostones and local limestones. Many carbonate shelves on passive margins are rimmed. The development of this Upper Cambrian rimmed shelf along the northwest margin of the MVG suggests that failed rifts can also localized such rims.

  1. Morphostructural evidence for Recent/active extension in Central Tanzania beyond the southern termination of the Kenya Rift.

    NASA Astrophysics Data System (ADS)

    Le Gall, B.; Rolet, J.; Gernigon, L.; Ebinger, C.; Gloaguen, R.

    2003-04-01

    The southern tip zone of the Kenya Rift on the eastern branch of the East African System is usually thought to occur in the so-called North Tanzanian Divergence. In this region, the narrow (50 km-wide) axial graben of southern Kenya splays southwards, via a major EW-trending volcanic lineament, into a 200 km-wide broad rifted zone with three separate arms of normal faulting and tilted fault blocks (Eyasi, Manyara and Pangani arms from W to E). Remote sensing analysis from Central Tanzania demonstrates that rift morphology exists over an area lying 400 km beyond the southern termination of the Kenya Rift. The most prominent rift structures are observed in the Kilombero region and consist of a 100 km-wide range of uplifted basement blocks fringed to the west by an E-facing half-graben inferred to reach depths of 6-8 km from aeromagnetic dataset. Physiographic features (fault scarps), and river drainage anomalies suggest that the present-day rift pattern in the Kilombero extensional province principally results from Recent/Neogene deformation. That assumption is also supported by the seismogenic character of a number of faults. The Kilombero half-graben is superimposed upon an earlier rift system, Karoo in age, which is totally overprinted and is only evidenced from its sedimentary infill. On the other hand, the nature and thickness of the inferred Neogene synrift section is still unknown. The Kilombero rifted zone is assumed to connect northwards into the central rift arm (Manyara) of the South Kenya Rift via a seismically active transverse fault zone that follows ductile fabrics within the Mozambican crystalline basement. The proposed rift model implies that incipient rifting propagates hroughout the cold and strong crust/lithosphere of Central Tanzania along Proterozoic (N140=B0E) basement weakness zones and earlier Karoo (NS)rift structures. A second belt of Recent-active linked fault/basins also extends further East from the Pangani rift arm to the offshore

  2. Evidence for Late-Paleozoic brine migration in Cambrian carbonate rocks of the central and southern Appalachians: Implications for Mississippi Valley-type sulfide mineralization

    USGS Publications Warehouse

    Hearn, P.P.; Sutter, J.F.; Belkin, H.E.

    1987-01-01

    Many Lower Paleozoic limestones and dolostones in the Valley and Ridge province of the central and southern Appalachians contain 10 to 25 weight percent authigenic potassium feldspar. This was considered to be a product of early diagenesis, however, 40Ar 39Ar analyses of overgrowths on detrital K-feldspar in Cambrian carbonate rocks from Pennsylvania, Maryland, Virginia, and Tennessee yield Late Carboniferous-Early Permian ages (278-322 Ma). Simple mass balance calculations suggest that the feldspar could not have formed isochemically, but required the flux of multiple pore volumes of fluid through the rocks, reflecting regional fluid migration events during the Late-Paleozoic Alleghanian orogeny. Microthermometric measurements of fluid inclusions in overgrowths on detrital K-feldspar and quartz grains from unmineralized rocks throughout the study area indicate homogenization temperatures from 100?? to 200??C and freezing point depressions of -14?? to -18.5??C (18-21 wt.% NaCl equiv). The apparent similarity of these fluids to fluid inclusions in ore and gangue minerals of nearby Mississippi Valley-type (MVT) deposits suggests that the regional occurrences of authigenic K-feldspar and MVT mineralization may be genetically related. This hypothesis is supported by the discovery of authigenic K-feldspar intergrown with sphalerite in several mines of the Mascot-Jefferson City District, E. Tennessee. Regional potassic alteration in unmineralized carbonate rocks and localized occurrences of MVT mineralization are both explainable by a gravity-driven flow model, in which deep brines migrate towards the basin margin under a hydraulic gradient established during the Alleghanian orogeny. The authigenic K-feldspar may reflect the loss of K during disequilibrium cooling of the ascending brines. MVT deposits are probably localized manifestations of the same migrating fluids, occurring where the necessary physical and chemical traps are present. ?? 1987.

  3. Evidence for Late-Paleozoic brine migration in Cambrian carbonate rocks of the central and southern Appalachians: Implications for Mississippi Valley-type sulfide mineralization

    NASA Astrophysics Data System (ADS)

    Hearn, Paul P., Jr.; Sutter, John F.; Belkin, Harvey E.

    1987-05-01

    Many Lower Paleozoic limestones and dolostones in the Valley and Ridge province of the central and southern Appalachians contain 10 to 25 weight percent authigenic potassium feldspar. This was considered to be a product of early diagenesis, however, 40Ar /39Ar analyses of overgrowths on detrital K-feldspar in Cambrian carbonate rocks from Pennsylvania, Maryland, Virginia, and Tennessee yield Late Carboniferous-Early Permian ages (278-322 Ma). Simple mass balance calculations suggest that the feldspar could not have formed isochemically, but required the flux of multiple pore volumes of fluid through the rocks, reflecting regional fluid migration events during the Late-Paleozoic Alleghanian orogeny. Microthermometric measurements of fluid inclusions in overgrowths on detrital K-feldspar and quartz grains from unmineralized rocks throughout the study area indicate homogenization temperatures from 100° to 200°C and freezing point depressions of -14° to -18.5°C (18-21 wt.% NaCl equiv). The apparent similarity of these fluids to fluid inclusions in ore and gangue minerals of nearby Mississippi Valley-type (MVT) deposits suggests that the regional occurrences of authigenic K-feldspar and MVT mineralization may be genetically related. This hypothesis is supported by the discovery of authigenic K-feldspar intergrown with sphalerite in several mines of the Mascot-Jefferson City District, E. Tennessee. Regional potassic alteration in unmineralized carbonate rocks and localized occurrences of MVT mineralization are both explainable by a gravity-driven flow model, in which deep brines migrate towards the basin margin under a hydraulic gradient established during the Alleghanian orogeny. The authigenic K-feldspar may reflect the loss of K during disequilibrium cooling of the ascending brines. MVT deposits are probably localized manifestations of the same migrating fluids, occurring where the necessary physical and chemical traps are present.

  4. Systematic variations in stress state in the southern San Joaquin Valley: Inferences based on well-bore data and contemporary seismicity

    SciTech Connect

    Castillo, D.A.; Zoback, M.D. )

    1994-08-01

    Analysis of stress-induced well-bore breakouts in 35 wells from 10 production fields in the southern San Joaquin Valley (SSJV) indicates systematic spatial variations in the direction of the maximum horizontal stresses at three different scales. First, the regional northeast-southwest compressional stress direction seen along the western margin of the San Joaquin Valley in the Elk Hills, Kettleman Hills, and Coalinga areas, gradually changes to approximately north-south compression over a distance of 10-20 km in the SSJV. This major excursion in the stress field seen in the Yowlumne, Yowlumne North, Paloma, and Rio Viejo production fields represents an approximately 40[degrees] counterclockwise rotation in the direction of the maximum horizontal stress (MHS). This systematic reorientation is consistent with approximately north-south convergence as seen in the local fold axes and reverse faults of Pliocene age and younger. Second, at the extreme south of the SSJV in the San Emidio, Los Lobos, Pleito, Wheeler Ridge, and North Tejon fields, another systematic, but localized, reorientation in the stress field indicates an abrupt change to an approximately east-northeast-west-southwest compression over a distance of a few kilometers. This latter reorientation of MHS stress direction, which is inconsistent with the local east-west-trending fold axes and thrust faults, represents a 40-50[degrees] clockwise rotation in the stresses; this reorientation appears to be limited to oil production fields located within the inferred hanging wall of the White Wolf fault that ruptured during the 1952 Kern County earthquake. Inversion of earthquake focal mechanisms of events located below the perturbed stress field indicates approximately north-south compression. The stress drop associated with the 1952 earthquake may have been responsible for rotating the MHS stress direction, implying that the remote horizontal stresses are comparable in magnitude. 53 refs., 16 refs., 2 tabs.

  5. Messinian Salinity Crisis and Course of Messinian Valleys in the Southern Shelf of the Sea of Marmara

    NASA Astrophysics Data System (ADS)

    Çifçi, Günay; Barın, Burcu; Okay, Seda; Dondurur, Derman; Sorlien, Christopher; Suc, Jean-Pierre; Lericolais, Gilles

    2015-04-01

    The Messinian Salinity Crisis widely accepted as one of the most interesting events concerning the Mediterranean marine environment in the earth's geological history. Late Miocene tectonic changes in Mediterranean-Atlantic connectivity caused this huge event. The Sea of Marmara region has been improperly considered as a gateway between the Paratethys and Mediterranean since the Middle Miocene. However, it is a very important location for paleoclimatic research including the sea level change associated with the Messinian Salinity Crisis. Although considerable work has been carried out on the Messinian Salinity Crisis, very little has been reported on the status of the Marmara Sea during the Messinian. The case study includes the southern shelf and North İmrali Basin of the Marmara Sea, which is in the region located from the Çanakkale Strait (Dardanelles) to İmralı Island. The structural and stratigraphic interpretation were carried out using high resolution multi-channel seismic reflection (MCS) data which were collected with the facilities of Seismic Laboratory (SeisLab) in the Institute of Marine Sciences and Technology and R/V K. Piri Reis belonging to Dokuz Eylül University under the frame of several projects including TUBİTAK-NSF. Seismic profiles acquired in southern shelf of the Marmara Sea suggest that Messinian fluvial erosion has occurred at the base of all the main sub-basins. The southern shoreline has provided well-preserved evidence of Messinian fluvial erosion followed by the post-crisis marine reflooding. Interpretation is focused on the nature of erosion related to this acoustic basement and to a major angular unconformity that may merge with it. The basement and erosionalsurface are interpreted in the Çanakkale outletandon the southern shelf of the Sea of Marmara. A buried East-West to NW-SE channel cut into acoustic basement that may belong to the Messinian period was interpreted on the MCS data. For instance, based on interpretation of

  6. Emergency Assessment of Debris-Flow Hazards from Basins Burned by the 2007 Slide and Grass Valley Fires, San Bernardino County, Southern California

    USGS Publications Warehouse

    Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Bauer, Mark A.; Stitt, Susan C.; Knifong, Donna L.; McNamara, Bernard J.; Roque, Yvonne M.

    2007-01-01

    INTRODUCTION The objective of this report is to present a preliminary emergency assessment of the potential for debris-flow generation from basins burned by the Slide and Grass Valley Fires in San Bernardino County, southern California in 2007. Debris flows are among the most hazardous geologic phenomena; debris flows that followed wildfires in southern California in 2003 killed 16 people and caused tens of millions of dollars of property damage. A short period of even moderate rainfall on a burned watershed can lead to debris flows. Rainfall that is normally absorbed into hillslope soils can run off almost instantly after vegetation has been removed by wildfire. This causes much greater and more rapid runoff than is normal from creeks and drainage areas. Highly erodible soils in a burn scar allow flood waters to entrain large amounts of ash, mud, boulders, and unburned vegetation. Within the burned area and downstream, the force of rushing water, soil, and rock can destroy culverts, bridges, roadways, and buildings, potentially causing injury or death. This emergency debris-flow hazard assessment is presented as relative ranking of the predicted median volume of debris flows that can issue from basin outlets in response to 3.50 inches (88.90 mm) of rainfall over a 3-hour period. Such a storm has a 10-year return period. The calculation of debris flow volume is based on a multiple-regression statistical model that describes the median volume of material that can be expected from a recently burned basin as a function of the area burned at high and moderate severity, the basin area with slopes greater than or equal to 30 percent, and triggering storm rainfall. Cannon and others (2007) describe the methods used to generate the hazard maps. Identification of potential debris-flow hazards from burned drainage basins is necessary to issue warnings for specific basins, to make effective mitigation decisions, and to help plan evacuation timing and routes.

  7. Paleomagnetic definition of crustal fragmentation and Quaternary block rotations in the east Ventura Basin and San Fernando valley, southern California

    NASA Astrophysics Data System (ADS)

    Levi, Shaul; Yeats, Robert S.

    2003-10-01

    Paleomagnetic studies of the Pliocene-Quaternary Saugus Formation in the eastern part of the western Transverse Ranges of California show that the crust is fragmented into small domains, tens of kilometers in linear dimension, identified by rotation of reverse-fault blocks. In an area approximately 35 × 25 km in the San Fernando valley and east Ventura Basin we identified four distinct domains. Two domains, southwest of and adjacent to the San Gabriel fault, are rotated clockwise: (1) The Magic Mountain domain, R = 30° ± 5° and (2) the Merrick syncline domain, R = 34° ± 6°. The Magic Mountain domain has rotated since 1 Ma. Both rotated sections occur in hanging walls of active reverse faults, the Santa Susana and San Fernando faults, respectively. Structural data suggest that the fault tip of the Santa Susana fault is the rotation pivot of the Magic Mountain domain. Two additional blocks are unrotated: (1) the Van Norman Lake domain, directly south of the Santa Susana fault, and (2) the Soledad Canyon domain, immediately across the San Gabriel fault from the Magic Mountain domain, suggesting that the San Gabriel fault might be a domain boundary. Our results suggest that part of the clockwise rotation of some Miocene and older rocks in this area might have occurred in the Quaternary. The Plio-Pleistocene fragmentation and clockwise rotations continue at present, based on geodetic data, and represent crustal response to diffuse, oblique dextral shearing within the San Andreas fault system.

  8. Subsurface geology of the late Tertiary and Quaternary water-bearing deposits of the southern part of the San Joaquin Valley, California

    USGS Publications Warehouse

    Croft, M.G.

    1972-01-01

    The study area, which includes about 5,000 square miles of the southern part of the San Joaquin Valley, is a broad structural trough of mostly interior drainage. The Sierra Nevada on the east is composed of consolidated igneous and metamorphic rocks of pre-Tertiary age. The surface of these rocks slopes 4?-6? southwestward from the foothills and underlies the valley. The Coast Ranges on the west consist mostly of complexly folded and faulted consolidated marine and nonmarine sedimentary rocks of Jurassic, Cretaceous, and Tertiary age, which dip eastward and overlie the basement complex. Unconsolidated deposits, of late Pliocene to Holocene age, blanket the underlying consolidated rocks in the valley and are the source of most of the fresh ground water. The unconsolidated deposits, the subject of this report, are divided into informal stratigraphic units on the basis of source of sediment, environment of deposition, and texture. Flood-basin, lacustrine, and marsh deposits are fine grained and underlie the valley trough. They range in age from late Pliocene to Holocene. These deposits, consisting of nearly impermeable gypsiferous fine sand, silt, and clay, are more than 3,000 feet thick beneath parts of Tulare Lake bed. In other parts of the trough, flood-basin, lacustrine, and marsh deposits branch into clayey or silty clay tongues designated by the letter symbols A to F. Three of these tongues, the E, C, and A clays, lie beneath large areas of the southern part of the valley. The E clay includes the Corcoran Clay Member of the Tulare Formation, the most extensive hydrologic confining layer in the valley. The E clay underlies about 3,500 square miles of bottom land and western slopes. The beds generally are dark-greenish-gray mostly diatomaceous silty clay of Pleistocene age. Marginally, the unit bifurcates into an upper and a lower stratum that contains thin beds of moderately yellowish-brown silt and sand. The E clay is warped into broad, gentle northwesterly

  9. A Validation Framework for Non-Point Source Simulation Models: Application to the Southern California Central Valley with Spatio-Temporally Heterogenous Source Rates

    NASA Astrophysics Data System (ADS)

    Kourakos, G.; Harter, T.

    2013-12-01

    Non-point source pollution on groundwater of agricultural regions is an alarming issue of global importance. The very large response times of contaminants which may vary from decades to centuries, require mitigation measures to be based on reliable modeling. Here we present a novel computational framework to assess and evaluate the dynamic, spatio-temporally distributed linkages between non-point sources above a groundwater basin and groundwater discharges to wells, streams, or other compliance discharge surfaces (CDSs) within a groundwater basin. The modeling framework allows for efficient evaluation of NPS pollution scenarios and of their short- and long-term effects on pollutant exceedance probabilities in CDSs. We apply the model to simulate 100 years of nitrate pollution at high resolution in a 2 million hectare semi-arid, irrigated agricultural region with a large diversity of crops, but also natural lands and urban areas, and highly heterogeneous, temporally variable loading landscape in the Southern California Central Valley. Results show that the timing of nitrate breakthrough in wells is significantly controlled by aquifer recharge and pumping rates in NPS areas and by the effective porosity of the aquifer system. MLast the model predictions are compared against a highly heterogeneous, spatio-temporally varying in space and time database of historic nitrate records and an attempt is made to compute the spatial distribution of nitrate half-life due to denitrification.

  10. Mechanics of Alleghenian emplacement of thrust sheets along the Blue Ridge-Valley and Ridge boundary in the Southern Appalachians

    SciTech Connect

    Bartholomew, M.J.

    1985-01-01

    The structural interaction between emplacement of the crystalline Blue Ridge thrust sheet (BRTS) and associated Alleghenian deformation in the Valley and Ridge can be, in part, deduced from the deformational style and sequence found in the structurally underlying Pulaski thrust sheet (PTS). Within the PTS both crosscutting and superimposed structural relationships indicate that Alleghenian deformation proceeded through 5 distinct stages involving the PTS. Structures formed during: stage A- as the BRTS ascended a footwall ramp over the PTS and the major lower level decollement zone (LLDZ) in Cambrian strata formed at the base of the PTS; stage B- as the coupled BRTS-PTS ascended a footwall ramp across Cambrian through middle Ordovician strata; stage C- as the PTS crossed the upper Ordovician through Devonian portion of that ramp; stage D- as the BRTS-PTS crossed upper Devonian and Mississippian rocks and reached the upper level decollement zone in Mississippian strata; stage E- post BRTS-PTS emplacement. Stage A was characterized by development of both an imbricate fan in the Rome Formation beneath the BRTS and a thick LLDZ containing abundant tectonic breccia near the Rome/Elbrook contact. The upper bounding surface (UBS) of this LLDZ is folded by broad folds and cut by faults formed during later stages as footwall tectonic slices were incorporated into the base of the PTS. Thus, regional fold and fault trends and relationships with the UBS suggest that most of the complex deformation and tectonic breccia found within the LLDZ formed prior to the PTS ascending the footwall ramp.

  11. Electrical resistivity imaging (ERI) and ground-penetrating radar (GPR) survey at the Giribaile site (upper Guadalquivir valley; southern Spain)

    NASA Astrophysics Data System (ADS)

    Martínez, J.; Rey, J.; Gutiérrez, L. M.; Novo, A.; Ortiz, A. J.; Alejo, M.; Galdón, J. M.

    2015-12-01

    The Giribaile archaeological site is one of the most important Iberian enclaves of the Alto Guadalquivir (Southern Spain). However, to date, only minimal excavation work has been performed at the site. Evaluation requires a preliminary, non-destructive general analysis to determine high-interest areas. This stage required a geophysical survey. Specifically, a 100 m2 grid was selected, where an initial campaign of nine electrical resistivity imaging (ERI) profiles was performed, where each profile was 111 m in length; these profiles were previously located using a detailed topographical survey. A total of 112 electrodes were used for each profile, spaced at 1 m apart with a Wenner-Schlumberger configuration. Secondly, 201 GPR profiles were created using a 500 MHz antenna. The 100 m long profiles were spaced 0.5 m apart and parallel to one another. The present research analyses the efficiency of each of these geophysical tools in supporting archaeological research. Using these methodologies, the position, morphology, and depth of different buried structures can be determined. 3D interpretation of the geophysical survey in 100 × 100 m grid allowed to differentiate structures square and rectangular, interesting buildings in a semicircle (interpreted as ovens) plus delineate different streets. From the geophysical survey follows the Carthaginian presence inside this ancient Iberian enclave.

  12. Escape of Sierra Nevada-Great Valley Block Motion Contributes to Upper-Plate Contraction Within the Southern Cascadia Margin Near Humboldt Bay, CA.

    NASA Astrophysics Data System (ADS)

    Williams, T. B.; Kelsey, H. M.; Freymueller, J. T.

    2002-12-01

    Recent GPS-derived site velocities (1993-2002) in northwestern California reveal that an additional mechanism other than subduction is in part accountable for observed upper plate contraction north of the migrating Mendocino triple junction. Sites at and near Cape Mendocino are moving approximately 30 mm/yr and are consistently oriented approximately N 10° W, sub-parallel to the southern Cascadia trench. Sites just north of latitude 40.4° N begin to be oriented east of north, sub-parallel to the Gorda-North America plate convergence direction. The transition from west-of-north to east-of-north site azimuths occurs 20 km north of the Mendocino Fault. The change in site azimuths is abrupt, with an eastward swing of 25°-30° occurring over a distance of approximately 8 km across the Eel River valley. North and east of Cape Mendocino, sites 50-300 km inland have velocities oriented west of north, consistent with the direction of northern Sierra Nevada-Great Valley (SNGV) block and Pacific-North America (P-NA) relative motion. Northern SNGV block motion is 11 mm/yr directed to the northwest. This velocity persists northwestward to within 50 km of the coast at the latitude of Humboldt Bay. Approximately 20 mm/yr of distributed P-NA motion occurs inland of Cape Mendocino across the northern projections of the Ma'acama and Bartlett Springs fault zones, and continues northward into the Humboldt Bay region. The direction of observed SNGV motion is obliquely convergent to the P-NA relative motion direction. The observed convergence between SNGV and the Coast Ranges begins approximately 130 km inland of the coast near Weaverville, CA. We observe 3-6 mm/yr of roughly east-west contraction in that area, which is near the location of the highest topography in the northern Coast Ranges. Near Humboldt Bay, NE-SW convergence of 16+/-2 mm/yr occurs from the coast to approximately 50 km inland. After removing an estimate of the interseismic subduction zone signal from the

  13. Analysis of particulate matter in anthropized areas characterized by the presence of crude oil pre-treatment plants: The case study of the Agri Valley (Southern Italy)

    NASA Astrophysics Data System (ADS)

    Trippetta, Serena; Caggiano, Rosa; Telesca, Luciano

    2013-10-01

    Simultaneous measurements of PM10, PM2.5 and PM1 (i.e., aerosol particles with aerodynamic diameter less than 10, 2.5 and 1 μm, respectively) daily mass concentrations and daily particle number concentration were performed for the first time in Agri Valley (Basilicata Region - Southern Italy) from July to November 2011. This area is characterized by anthropogenic activities having high potential environmental and human health impacts. In fact, the Agri Valley houses the largest European on-shore reservoir and the largest crude oil pre-treatment plant within an anthropized area. The PM measurements were analyzed combining an innovative statistical methodology, the Singular Spectral Analysis, with forecast models and remote sensing observations. Our findings show that most of the PM collected was made up of particles in the fine and sub-micrometric fractions (i.e., PM2.5 and PM1, respectively) very likely originated by common anthropogenic sources. Moreover, PM2.5 and PM1 daily mass concentrations were characterized by a slightly increasing trend that could be related to the contribution of local sources, such as the crude oil pre-treatment plant, whose combustion processes also produce the emission of particles mainly in the fine and sub-micrometric size ranges. The integrated use of model forecasts, satellite observations and in-situ measurements shows that the only PM10 exceedance was affected by the contribution of Saharan dust, while the three PM2.5 exceedances were mainly due to local anthropogenic sources. Finally, the analysis of the PM10 and PM2.5 Air Quality Index (AQI) values shows that air quality was always “good” with respect to PM10 and “moderate” with respect to PM2.5 suggesting that fine particles, if they will be not kept under control, should represent a real problem also posing health risks to the population living close to the crude oil pre-treatment plant.

  14. Holocene planform change in broad valleys in the Southern Rocky Mountains: the role of vegetation type and beaver in shaping long-term channel complexity

    NASA Astrophysics Data System (ADS)

    Polvi-Pilgrim, L. E.; Wohl, E.

    2012-04-01

    Over the past decade, researchers have shown the importance of streambank vegetation in forming meandering channels. Recent work has also showed the importance of beaver in creating a more heterogeneous landscape, in terms of channel planform and complexity, sedimentation, and riparian vegetation. Streambank vegetation and beavers interact as ecosystem engineers to determine long-term channel planform, floodplain processes, and complexity. We use studies of Holocene beaver aggradation and effects on channel complexity, in addition to measurements of added bank strength by various riparian vegetation types, to predict Holocene planform change in broad (>200 m, disconnected from hillslopes), high-elevation (>2300 m) valleys of the Colorado Front Range in the Southern Rocky Mountains. Sediment core analyses and shallow subsurface geophysical measurements indicate that post-glacial beaver-related aggradation is significant. Additionally, historical and field evidence from the last century, when the beaver population steadily declined, shows that beaver contribute to the formation of a complex, multi-thread channel network. Streambank vegetation in the Colorado Front Range can be categorized based on its ability to provide added strength to the streambank, where riparian or rhizomatous shrubs and trees provide more strength than xeric trees or non-rhizomatous graminoids and herbs, depending on the bank texture and hydrologic conditions. Assuming a snowmelt-dominated flow regime in a gravel-bed channel system, four planform regimes are identified based on beaver populations and the abundance and presence of xeric or riparian vegetation. Following deglaciation, without beaver or bank-stabilizing vegetation, (1) a braided channel formed. The introduction of riparian vegetation and a more stable flow regime triggered a transition to (2) a meandering channel, which in turn provided habitat for beaver, allowing the formation of (3) a complex multi-thread channel system. The

  15. Effects of source rocks, soil features and climate on natural gamma radioactivity in the Crati valley (Calabria, Southern Italy).

    PubMed

    Guagliardi, Ilaria; Rovella, Natalia; Apollaro, Carmine; Bloise, Andrea; De Rosa, Rosanna; Scarciglia, Fabio; Buttafuoco, Gabriele

    2016-05-01

    The study, which represents an innovative scientific strategy to approach the study of natural radioactivity in terms of spatial and temporal variability, was aimed to characterize the background levels of natural radionuclides in soil and rock in the urban and peri-urban soil of a southern Italy area; to quantify their variations due to radionuclide bearing minerals and soil properties, taking into account nature and extent of seasonality influence. Its main novelty is taking into account the effect of climate in controlling natural gamma radioactivity as well as analysing soil radioactivity in terms of soil properties and pedogenetic processes. In different bedrocks and soils, activities of natural radionuclides ((238)U, (232)Th (4) K) and total radioactivity were measured at 181 locations by means of scintillation γ-ray spectrometry. In addition, selected rocks samples were collected and analysed, using a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS) and an X-Ray Powder Diffraction (XRPD), to assess the main sources of radionuclides. The natural-gamma background is intimately related to differing petrologic features of crystalline source rocks and to peculiar pedogenetic features and processes. The radioactivity survey was conducted during two different seasons with marked changes in the main climatic characteristics, namely dry summer and moist winter, to evaluate possible effects of seasonal climatic variations and soil properties on radioactivity measurements. Seasonal variations of radionuclides activities show their peak values in summer. The activities of (238)U, (232)Th and (4) K exhibit a positive correlation with the air temperature and are negatively correlated with precipitations.

  16. Effects of source rocks, soil features and climate on natural gamma radioactivity in the Crati valley (Calabria, Southern Italy).

    PubMed

    Guagliardi, Ilaria; Rovella, Natalia; Apollaro, Carmine; Bloise, Andrea; De Rosa, Rosanna; Scarciglia, Fabio; Buttafuoco, Gabriele

    2016-05-01

    The study, which represents an innovative scientific strategy to approach the study of natural radioactivity in terms of spatial and temporal variability, was aimed to characterize the background levels of natural radionuclides in soil and rock in the urban and peri-urban soil of a southern Italy area; to quantify their variations due to radionuclide bearing minerals and soil properties, taking into account nature and extent of seasonality influence. Its main novelty is taking into account the effect of climate in controlling natural gamma radioactivity as well as analysing soil radioactivity in terms of soil properties and pedogenetic processes. In different bedrocks and soils, activities of natural radionuclides ((238)U, (232)Th (4) K) and total radioactivity were measured at 181 locations by means of scintillation γ-ray spectrometry. In addition, selected rocks samples were collected and analysed, using a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS) and an X-Ray Powder Diffraction (XRPD), to assess the main sources of radionuclides. The natural-gamma background is intimately related to differing petrologic features of crystalline source rocks and to peculiar pedogenetic features and processes. The radioactivity survey was conducted during two different seasons with marked changes in the main climatic characteristics, namely dry summer and moist winter, to evaluate possible effects of seasonal climatic variations and soil properties on radioactivity measurements. Seasonal variations of radionuclides activities show their peak values in summer. The activities of (238)U, (232)Th and (4) K exhibit a positive correlation with the air temperature and are negatively correlated with precipitations. PMID:26891362

  17. Out-of-phase decadal changes in boreal summer rainfall between Yellow-Huaihe River Valley and southern China around 2002/2003

    NASA Astrophysics Data System (ADS)

    Ha, Yao; Zhong, Zhong; Chen, Haishan; Hu, Yijia

    2016-07-01

    This study investigates the decadal variability of rainfall over China in boreal summer (June-August) since the early 1990s. Results show that the rainfall experiences an abrupt decadal change at around 2002/2003. The decadal change is statistically significant and characterized by an out-of-phase pattern between southern China (SC) and the Yellow-Huaihe River Valley (YHRV). The rainfall over SC decreases during the decade 2003-2012 compared to that in the preceding decade 1993-2002. A simultaneous decadal increase in rainfall has occurred over the YHRV. Meanwhile, a significant sea surface temperature warming appears over the western Pacific Ocean and the northern Indian Ocean after 2002 on the decadal time scale. Further analysis reveals that enhanced convections are activated over the tropical regions between 130°E and 160°E and west of 80°E due to the SST anomalies, which induce the dry air in an area of anomalous subsidence located over SC and the northern South China Sea (SCS) via zonal circulation. Accompanied by the anomalous descending flow over the northern SCS, tropical cyclone (TC) activities in the SCS also experience a concurrent decadal reduction. The decrease in landfall TCs contributes to the decadal decrease in SC rainfall since 2003. Corresponding to the anomalous descending motion that is dominant south of 30°N, an anomalous moist ascending flow develops over the YHRV at around 35°N. Meanwhile, the western Pacific subtropical high becomes stronger and extends further westward during 2003-2012, leading to enhanced moisture transport by the southwesterly in the northwestern flank of subtropical high. As a result, more precipitation occurs over the YHRV. The above analysis has revealed the physical-dynamical processes involved in the decadal changes in rainfall over China. The mechanisms behind the out-of-phase pattern of rainfall changes between SC and the YHRV that occurred at 2002/2003 are explored.

  18. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Tulare Lake bed area, southern San Joaquin Valley, California, 1986-87

    USGS Publications Warehouse

    Schroeder, R.A.; Palawski, D.U.; Skorupa, J.P.

    1988-01-01

    Concentrations of numerous toxic trace elements and pesticides were measured during 1986 in water, sediment, and biota from three areas near the Tulare Lake Bed, southern San Joaquin Valley, California: Kern National Wildlife Refuge, Pixley National Wildlife Refuge, and Westfarmers evaporation ponds about 5 mi west of Kern National Wildlife Refuge, to determine whether toxic constituents in agricultural-irrigation drainage pose a threat to beneficial uses of water, especially to uses by wildlife. Pesticide residues were found to be low at all three areas. Trace element concentrations were found to be comparatively low at the Kern and Pixley National Wildlife Refuge areas and high at the Westfarmers evaporation ponds. Dissolved selenium concentrations were < 1 micrograms/L (ug/L) in areas on and adjacent to the refuges, but ranged from 110 to 360 ug/L in the saline drainwater impounded in the evaporation ponds. The ratio of mean selenium concentrations in biota from Westfarmers ponds compared to biota from Kesterson National Wildlife Refuge (where adverse effects have been documented) is 5 for waterboatman, 2 for avocet liver, 1 for avocet eggs, and < 1 for widgeongrass. The low concentrations measured at Kern and Pixley National Wildlife Refuges suggest that trace elements and pesticides pose little threat to wildlife there; however, impounded subsurface drainage from agricultural irrigation does pose a threat to wildlife at the nearby Westfarmers ponds. Preliminary results of surveys conducted in 1987 indicated that there are adverse biological effects on shorebirds nesting at the ponds, although interpretation of the magnitude of the effects is premature, pending completion of ongoing studies by the U.S. Fish and Wildlife Service. (Author 's abstract)

  19. Status and understanding of groundwater quality in the two southern San Joaquin Valley study units, 2005-2006 - California GAMA Priority Basin Project

    USGS Publications Warehouse

    Burton, Carmen A.; Shelton, Jennifer L.; Belitz, Kenneth

    2012-01-01

    Groundwater quality in the southern San Joaquin Valley was investigated from October 2005 through March 2006 as part of the Priority Basin Project of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin Project is conducted by the U.S. Geological Survey (USGS) in collaboration with the California State Water Resources Control Board and the Lawrence Livermore National Laboratory. There are two study units located in the southern San Joaquin Valley: the Southeast San Joaquin Valley (SESJ) study unit and the Kern County Subbasin (KERN) study unit. The GAMA Priority Basin Project in the SESJ and KERN study units was designed to provide a statistically unbiased, spatially distributed assessment of untreated groundwater quality within the primary aquifers. The status assessment is based on water-quality and ancillary data collected in 2005 and 2006 by the USGS from 130 wells on a spatially distributed grid, and water-quality data from the California Department of Public Health (CDPH) database. Data was collected from an additional 19 wells for the understanding assessment. The aquifer systems (hereinafter referred to as primary aquifers) were defined as that part of the aquifer corresponding to the perforation interval of wells listed in the CDPH database for the SESJ and KERN study units. The status assessment of groundwater quality used data from samples analyzed for anthropogenic constituents such as volatile organic compounds (VOCs) and pesticides, as well as naturally occurring inorganic constituents such as major ions and trace elements. The status assessment is intended to characterize the quality of untreated groundwater resources within the primary aquifers in the SESJ and KERN study units, not the quality of drinking water delivered to consumers. Although the status assessment applies to untreated groundwater, Federal and California regulatory and non-regulatory water-quality benchmarks that apply to drinking water are used

  20. Selenium in ecosystems within the mountaintop coal mining and valley-fill region of southern West Virginia-assessment and ecosystem-scale modeling

    USGS Publications Warehouse

    Presser, Theresa S.

    2013-01-01

    Coal and associated waste rock are among environmental selenium (Se) sources that have the potential to affect reproduction in fish and aquatic birds. Ecosystems of southern West Virginia that are affected by drainage from mountaintop coal mines and valleys filled with waste rock in the Coal, Gauley, and Lower Guyandotte watersheds were assessed during 2010 and 2011. Sampling data from earlier studies in these watersheds (for example, Upper Mud River Reservoir) and other mining-affected watersheds also are included to assess additional hydrologic settings and food webs for comparison. Basin schematics give a comprehensive view of sampled species and Se concentration data specific to location and date. Food-web diagrams document the progression of Se trophic transfer across suspended particulate material, invertebrates, and fish for each site to serve as the basis for developing an ecosystem-scale model to predict Se exposure within the hydrologic conditions and food webs of southern West Virginia. This approach integrates a site-specific predator’s dietary exposure pathway into modeling to ensure an adequate link to Se toxicity and, thus, to species vulnerability. Site-specific fish abundance and richness data in streams documented various species of chub, shiner, dace, darters, bass, minnow, sunfish, sucker, catfish, and central stoneroller (Campostoma anomalum), mottled sculpin (Cottus bairdii), and least brook lamprey (Lampetra aepyptera). However, Se assessment species for streams, and hence, model species for streams, were limited to creek chub (Semotilus atromaculatus) and central stoneroller. Both of these species of fish are generally considered to have a high tolerance for environmental stress based on traditional comparative fish community assessment, with creek chub being present at all sites. Aquatic insects (mayfly, caddisfly, stonefly, dobsonfly, chironomid) were the main invertebrates sampled in streams. Collection of suspended particulate material

  1. Introduction and establishment of tadpole shrimp Triops newberryi (Notostraca: Triopsidae) in a date garden for biological control of mosquitoes in the Coachella Valley, Southern California.

    PubMed

    Su, Tianyun; Mulla, Mir S

    2002-06-01

    Tadpole shrimp (TPS), Triops newberryi (Packard), has been reported to have a potential as a biocontrol agent for larval mosquitoes breeding in intermittently flooded habitats. To develop and promote this predator for controlling mosquitoes, a date garden devoid of preexisting TPS populations was chosen in the Coachella Valley, southern California in 2000 to receive introductions of TPS eggs and mature TPS. Mosquito control by TPS was assessed in the plots one year after their introductions. In a selected block on this ranch, 2 rows were stocked with TPS eggs, where soil containing approximately 2,000 eggs was spread over the surface of dry ground in each row before flooding. Another 2 rows were used for mature TPS introduction, where about 400 mature TPS were released into standing water in each row 1 day after flooding. After a single egg or mature TPS introduction, active TPS in water and viable eggs in dry surface soil were noted in increasing numbers during the 3-4 subsequent irrigations. Disking before irrigation, which turned the eggs over and mixed them into the soil column, reduced TPS egg populations at the soil surface and subsequent active TPS populations in standing water after irrigation. After one or two irrigations, viable eggs and active shrimp were found in centers adjacent to the introduced plots in the stocked rows. Ample evidence is presented to show that TPS populations were established after a single introduction of eggs or mature TPS. TPS eggs and/or newly hatched TPS were also carried into the neighboring rows across the borders by the overflowing irrigation water, and TPS populations became established there too, as active TPS were noted after each irrigation in the adjacent unstocked rows. Considering the ease and economical storage, transportation and handling, dessication--resistant eggs have advantages over mature TPS for field introductions. Mosquito control by TPS was assessed in rows with and without TPS in July 2001, one year after

  2. Vegetation and geomorphic significance of the riparian greenline in the Sprague River basin, southern Oregon: implications for biogeomorphic monitoring of riparian corridors in semi-arid mountain valleys

    NASA Astrophysics Data System (ADS)

    Hughes, M. L.; Leeseberg, C.

    2009-12-01

    Like many regions in the western U.S., valley-floor environments of the semi-arid Sprague River basin of southern Oregon are heavily irrigated and widely grazed by cattle. To better understand the impacts of grazing and other land uses on river quality, the Klamath Tribes have begun a long-term, basin-wide program aimed at: (1) establishing baseline geomorphic and vegetative conditions along the Sprague River and its tributaries, and (2) monitoring changes in these conditions over time. Because of its widespread use and ease of application, determining the composition of the lowest line of perennial vegetation above baseflow, or the “greenline,” has been included. The goal of this paper is to summarize results of 38 greenline surveys conducted at 19 sites in 2008-9 and to explore geomorphic hypotheses that may explain vegetation patterns evident in the surveys. Spikerush (Eleocharis ssp.) and reed-canary grass (Phalaris arudinacea) were the most commonly occurring vegetation in the greenline across all sites. Because these species are aggressive colonizers, they indicate high availability of fresh alluvium, which may be associated with sustained channel-bank disturbance. Sedges dominated some portions of the greenline at most of the sites, but occurred in less abundance. The late successional or early-to-late transitional state of these sedges, combined with their relatively low frequency, further supports the hypothesis that channel-bank systems remain chronically disturbed and dynamic. Grazing is common, but variable in intensity, at nearly all of the study sites, likely contributing to the persistence of channel-bank disturbance. Among meandering channels, the richness of dominant species (i.e., “community diversity”) was higher on the outer bends than on the inner bends of meanders at 10 of 12 sites. The variability of geomorphic surfaces (old floodplain, new floodplain, failed bank, accreted toe, etc.) incorporated in the greenline by the spatially

  3. Sources, trends and regional impacts of fine particulate matter in southern Mississippi Valley: significance of emissions from sources in the Gulf of Mexico coast

    NASA Astrophysics Data System (ADS)

    Chalbot, M.-C.; McElroy, B.; Kavouras, I. G.

    2013-01-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mineral/road dust, accounting for more than 90% of measured PM2.5 mass. The declining trend of PM2.5 mass (0.4 μg m-3 yr-1) was related to lower levels of SO42- (0.2 μg m-3 yr-1) due to SO2 reductions from point and mobile sources. The slower decline for NO3- particles (0.1 μg m-3 yr-1) was attributed to the spatial variability of NH3 in Midwest. The annual variation of biomass burning particles was associated with wildland fires in southeast and northwest US that are sensitive to climate changes. The four regions within 500 km from the receptor site, the Gulf Coast and southeast US accounted cumulatively for more than 65% of PM2.5 mass, nitrate, sulphate and biomass burning aerosol. Overall, more than 50% of PM2.5 and its sources originated from sources outside the state. Sources within the Gulf Coast and western Gulf of Mexico include 65% of the busiest ports in the US, intense marine traffic within 400 km of the coast burning rich in S diesel, and a large number of offshore oil and natural gas platforms and many refineries along the coast. This approach allowed for quantitatively assessing the impacts of transport from regions representing diverse mixtures of sources and weather conditions for different types of particles. The findings of this effort demonstrated the influences of emission controls on SO2 and NOx on PM2.5 mass, the potential effect of events (i.e. fires) sensitive to climate change phenomena on air pollution and the potential of offshore activities and shipping emissions to

  4. Sources, trends and regional impacts of fine particulate matter in southern Mississippi valley: significance of emissions from sources in the Gulf of Mexico coast

    NASA Astrophysics Data System (ADS)

    Chalbot, M.-C.; McElroy, B.; Kavouras, I. G.

    2013-04-01

    The sources of fine particles over a 10 yr period at Little Rock, Arkansas, an urban area in the southern Mississippi Valley, were identified by positive matrix factorization. The annual trends of PM2.5 and its sources, and their associations with the pathways of air mass backward trajectories were examined. Seven sources were apportioned, namely, primary traffic particles, secondary nitrate and sulphate, biomass burning, diesel particles, aged/contaminated sea salt and mineral/road dust, accounting for more than 90% of measured PM2.5 (particles with aerodynamic diameter less than 2.5 μm) mass. The declining trend of PM2.5 mass (0.4 μg m-3 per year) was related to lower levels of SO42- (0.2 μg m-3 per year) due to SO2 reductions from point and mobile sources. The slower decline for NO3- particles (0.1 μg m-3 per year) was attributed to the increasing NH3 emissions in the Midwest. The annual variation of biomass burning particles was associated with fires in the southeast and northwest US. Of the four regions within 500 km from the receptor site, the Gulf Coast and the southeast US accounted cumulatively for more than 65% of PM2.5 mass, nitrate, sulphate and biomass burning aerosol. Overall, more than 50% of PM2.5 and its components originated from sources outside the state. Sources within the Gulf Coast and western Gulf of Mexico include 65% of the busiest ports in the US, intense marine traffic within 400 km of the coast burning rich in S diesel, and a large number of offshore oil and natural gas platforms and many refineries. This approach allowed for the quantitative assessment of the impacts of transport from regions representing diverse mixtures of sources and weather conditions for different types of particles. The findings of this effort demonstrated the influences of emission controls on SO2 and NOx on PM2.5 mass, the potential effect of events (i.e. fires) sensitive to climate change phenomena on air pollution and the potential of offshore activities

  5. Introduction and establishment of tadpole shrimp Triops newberryi (Notostraca: Triopsidae) in a date garden for biological control of mosquitoes in the Coachella Valley, Southern California.

    PubMed

    Su, Tianyun; Mulla, Mir S

    2002-06-01

    Tadpole shrimp (TPS), Triops newberryi (Packard), has been reported to have a potential as a biocontrol agent for larval mosquitoes breeding in intermittently flooded habitats. To develop and promote this predator for controlling mosquitoes, a date garden devoid of preexisting TPS populations was chosen in the Coachella Valley, southern California in 2000 to receive introductions of TPS eggs and mature TPS. Mosquito control by TPS was assessed in the plots one year after their introductions. In a selected block on this ranch, 2 rows were stocked with TPS eggs, where soil containing approximately 2,000 eggs was spread over the surface of dry ground in each row before flooding. Another 2 rows were used for mature TPS introduction, where about 400 mature TPS were released into standing water in each row 1 day after flooding. After a single egg or mature TPS introduction, active TPS in water and viable eggs in dry surface soil were noted in increasing numbers during the 3-4 subsequent irrigations. Disking before irrigation, which turned the eggs over and mixed them into the soil column, reduced TPS egg populations at the soil surface and subsequent active TPS populations in standing water after irrigation. After one or two irrigations, viable eggs and active shrimp were found in centers adjacent to the introduced plots in the stocked rows. Ample evidence is presented to show that TPS populations were established after a single introduction of eggs or mature TPS. TPS eggs and/or newly hatched TPS were also carried into the neighboring rows across the borders by the overflowing irrigation water, and TPS populations became established there too, as active TPS were noted after each irrigation in the adjacent unstocked rows. Considering the ease and economical storage, transportation and handling, dessication--resistant eggs have advantages over mature TPS for field introductions. Mosquito control by TPS was assessed in rows with and without TPS in July 2001, one year after

  6. Timing, Duration, and Effects of Droughts in the Southern Sierra Nevada and San Joaquin Valley, CA Over the Last 2000 Years

    NASA Astrophysics Data System (ADS)

    Adams, K. D.; Negrini, R. M.; Rajagopal, S.; Cook, E. R.

    2015-12-01

    The Central Valley of California is one of the most prolific agricultural areas in the U.S., providing about 25 % of the nation's food. This system is reliant on winter snows in the Sierra Nevada that gradually melt through the spring, but over the last 4 years California has been in the grip of its worst drought of the last 150 years. The question remains, however, how unusual is this drought when compared to previous events over longer time scales? We used moisture sensitive tree-ring chronologies from the Living Blended Drought Atlas of Cook et al. (2010) to reconstruct annual discharges over the last 2000 years for the Kings, Kaweah, Tule, and Kern rivers in the southern Sierra and routed this discharge into a Tulare Lake water balance model to simulate lake-level fluctuations over this same time period. Although the current drought represents the driest consecutive four year period over the past 2000 years, in terms of discharge volumes, there are multiple periods of more severe, longer term drought represented by extended periods of low lake levels. Significant low-lake periods (< 61 m) include 793-814, 906-933, and 1140-1158, all of which occurred during the Medieval Climate Anomaly. Conversely, lake levels were predominately high during the ensuing Little Ice Age, separated by brief periods of low lake levels. Under natural flow conditions, the 1923-1935 drought would have lowered lake level to about 58 m, which is about 2 m lower than where lake level would have been in the current drought. Wavelet analyses of the streamflow and lake-level records reveal different periodicities of drought and wet conditions because lake-level is a state variable that changes relatively slowly, depending on inflow, precipitation on the lake, evaporation rate, and the hypsometry of the basin, whereas streamflow is a flux that responds immediately to climate perturbations. The streamflow records have a dominant period of 2-8 yrs but lake-level fluctuations follow longer

  7. Coupling Between Hydrogeology And Progressive Failure Of Mountainous Rock Slopes: Field And Modelling Results From La Clapiere Valley (Southern Alps, France)

    NASA Astrophysics Data System (ADS)

    Guglielmi, Y.; Cappa, F.

    2005-12-01

    Hydromechanical effects of water flow within fractures are predominant effects that induce strength decrease of rock slopes and progressive failure propagation. A multi-parametric approach was conducted on the 70 km long La Clapière valley (Southern French Alps) consisting in mapping geology, hydrogeology and gravitational features, dating gravitational scarps and in monitoring slope springs yields, water chemistry and slope deformation for more than 10 years. First a hydromechanical model of rock slope behaviour was established and compared to bibliography. Second, taking this model as a reference, relationships between slope failure and hydrogeology were parametrically investigated using the two-dimensional distinct element method program UDEC. Rock slopes general structure consists in a superficial weathered zone (a few hundreds of meters thick) overlapping a deep intact zone. Penetrative discontinuities cut both zones. In the weathered zone tensile cracks scatter from the middle to the top of the slope. Large landslides are located at the slope foot. A perched saturated-with-water zone nested within the cracks is drained towards the slope foot through the landslides. Annual precipitation infiltrations induce hydromechanical effects that participate to the rock strength decrease through tilting and diffuse shear plane development. Such progressive failure propagation lasts over thousands of years (10 000 years in the studied area). Numerical study shows that, at the early stage of slope alteration, hydrostatic pressures are concentrated in tensile features of the upper part of the slope for moderate infiltration yield (mean inter-annual value). Pressure increase induces fracture shear dilation and traction opening that in reverse modifies flow paths and pressure. Consequence is tilting of rock columns with progressive diffuse failure at the columns' foot. A thick high porosity and high permeability weathered layer (up to hundreds meters thick) is generated

  8. How a geology map of the Upper Santa Maria Valley in the Southern Swiss Alps played a critical role in solving a hydrogeologic enigma

    NASA Astrophysics Data System (ADS)

    Otz, M. H.; Otz, I.

    2010-12-01

    Several regional-scale, fluorescent dye-tracing tests recently showed counter-intuitive, tectonically influenced, preferential ground water flow from the Piora Region via the Santa Maria Valley to the di Campo Valley. Losing rivers of the Piora Valley recharge the Triassic Piora Aquifer at an average rate of 20,000 m3/d and hydrologic budgets suggest that half of the Upper Santa Maria discharge originates from the Piora Region. The geologic map of the Upper Santa Maria Valley presented a partial solution to the hydrogeologic puzzle of the Piora Aquifer, thus facilitating construction of the AlpTransit railway tunnel (the longest on Earth). The autochthonous Lucomagno Triassic of the Gotthard Massif (cargneules), the allochthonous Frodalera-Peiden Triassic (sugar dolomites, para-gneises, quartzites, green phyllites), the Stgir Series of the Lower Jurassic (sandy limestones and quartzites), the Inferno Series of the Middle Jurassic (coarse sandstones, limestones, shales), the Coroi Series of the Upper Jurassic (black shales), the crystalline Gotthard Massif (ortho-gneises), and the northern Penninic Nappe (para- and ortho-gneises, quartzites) are the main lithologies found in the outcrops of the Upper Santa Maria Valley. The highly weathered Triassic series found in the Piora and Upper Santa Maria Valley posed a potential hydrogeologic obstacle that was overcome by tunnel drillers in early 2010, for expected tunnel service by 2012.

  9. A stacked Late Quaternary fluvio-periglacial sequence from the Axe valley, southern England with implications for landscape evolution and Palaeolithic archaeology

    NASA Astrophysics Data System (ADS)

    Brown, A. G.; Basell, L. S.; Toms, P. S.

    2015-05-01

    The current model of mid-latitude late Quaternary terrace sequences, is that they are uplift-driven but climatically controlled terrace staircases, relating to both regional-scale crustal and tectonic factors, and palaeohydrological variations forced by quasi-cyclic climatic conditions in the 100 K world (post Mid Pleistocene Transition). This model appears to hold for the majority of the river valleys draining into the English Channel which exhibit 8-15 terrace levels over approximately 60-100 m of altitudinal elevation. However, one valley, the Axe, has only one major morphological terrace and has long-been regarded as anomalous. This paper uses both conventional and novel stratigraphical methods (digital granulometry and terrestrial laser scanning) to show that this terrace is a stacked sedimentary sequence of 20-30 m thickness with a quasi-continuous (i.e. with hiatuses) pulsed, record of fluvial and periglacial sedimentation over at least the last 300-400 K yrs as determined principally by OSL dating of the upper two thirds of the sequence. Since uplift has been regional, there is no evidence of anomalous neotectonics, and climatic history must be comparable to the adjacent catchments (both of which have staircase sequences) a catchment-specific mechanism is required. The Axe is the only valley in North West Europe incised entirely into the near-horizontally bedded chert (crypto-crystalline quartz) and sand-rich Lower Cretaceous rocks creating a buried valley. Mapping of the valley slopes has identified many large landslide scars associated with past and present springs. It is proposed that these are thaw-slump scars and represent large hill-slope failures caused by Vauclausian water pressures and hydraulic fracturing of the chert during rapid permafrost melting. A simple 1D model of this thermokarstic process is used to explore this mechanism, and it is proposed that the resultant anomalously high input of chert and sand into the valley during terminations

  10. East African Rift Valley, Kenya

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This rare, cloud free view of the East African Rift Valley, Kenya (1.5N, 35.5E) shows a clear view of the Turkwell River Valley, an offshoot of the African REift System. The East African Rift is part of a vast plate fracture which extends from southern Turkey, through the Red Sea, East Africa and into Mozambique. Dark green patches of forests are seen along the rift margin and tea plantations occupy the cooler higher ground.

  11. Selenium in ecosystems within the mountaintop coal mining and valley-fill region of southern West Virginia-assessment and ecosystem-scale modeling

    USGS Publications Warehouse

    Presser, Theresa S.

    2013-01-01

    Investigating the presence and variability of prey and predator species in demographically open systems such as streams also is key to model outcomes given the overall environmental stressors (for example, general landscape change, food-web disruption, recolonization potential) imposed on the composition of biological communities in coal mining and valley-fill affected watersheds

  12. Desegregation in the South San Joaquin Valley.

    ERIC Educational Resources Information Center

    Serrano, Rodolfo G.

    Notably isolated from the large metropolitan centers by geography and predominantly agricultural in its economy, Kern County is California's third largest county in land area. About one-third of the county is situated on the flat valley floor at the extreme southern end of the San Joaquin Valley. The area relies heavily on Chicano and Black manual…

  13. Strontium isotopic signatures of the streams and lakes of Taylor Valley, Southern Victoria Land, Antarctica: Chemical weathering in a polar climate

    USGS Publications Warehouse

    Lyons, W.B.; Nezat, C.A.; Benson, L.V.; Bullen, T.D.; Graham, E.Y.; Kidd, J.; Welch, K.A.

    2002-01-01

    We have collected and analyzed a series of water samples from three closed-basin lakes (Lakes Bonney, Fryxell, and Hoare) in Taylor Valley, Antarctica, and the streams that flow into them. In all three lakes, the hypolimnetic waters have different 87Sr/86Sr ratios than the surface waters, with the deep water of Lakes Fryxell and Hoare being less radiogenic than the surface waters. The opposite occurs in Lake Bonney. The Lake Fryxell isotopic ratios are lower than modern-day ocean water and most of the whole-rock ratios of the surrounding geologic materials. A conceivable source of Sr to the system could be either the Cenozoic volcanic rocks that make up a small portion of the till deposited in the valley during the Last Glacial Maximum or from marble derived from the local basement rocks. The more radiogenic ratios from Lake Bonney originate from ancient salt deposits that flow into the lake from Taylor Glacier and the weathering of minerals with more radiogenic Sr isotopic ratios within the tills. The Sr isotopic data from the streams and lakes of Taylor Valley strongly support the notion documented by previous investigators that chemical weathering has been, and is currently, a major process in determining the overall aquatic chemistry of these lakes in this polar desert environment.

  14. The organic and mineral matter contents in deposits infilling floodplain basins: Holocene alluviation record from the Kłodnica and Osobłoga river valleys, southern Poland

    NASA Astrophysics Data System (ADS)

    Wójcicki, K. J.; Marynowski, L.

    2012-07-01

    The work examines the timing and environmental conditions of floodplain sedimentation in the valleys of the upland Kłodnica and piedmont Osobłoga rivers in the Upper Odra River basin. A distribution of 52 14C-ages shows relatively high floodplain sedimentation at the Late Glacial-Holocene transition, more stable floodplain environments since the Early (in the Kłodnica Valley) and Middle Holocene (in the Osobłoga Valley) and a gradual increase in floodplain deposition in the Late Holocene (since < 3.4 kyr BP). Organic matter [OM] and mineral matter [MM] fluctuations were correlated with variables responsible for the activation of erosion (i.e. vegetation changes, human impact and hydrological events) as well as factors affecting the local record of sedimentation (i.e. valley morphology, hydrologic conditions and episodes of local erosion). A clear relationship is shown between an increase in alluviation and climate- or human-induced extension of unforested areas. The deposition of mineral-rich sediments increases rapidly during periods characterized by non-arboreal pollen values exceeding approximately 8% in pollen diagrams. On the other hand, the results obtained do not confirm significant interactions between Holocene changes in forest composition and alluviation. Despite the settlement of agrarian groups, the sedimentary record of human activity in the Osobłoga catchment is very poor during the Neolithic and early Bronze Age. A large-scale alluviation of the Osobłoga and Kłodnica valleys was initiated during the settlement of people of the Lusatian culture from the middle Bronze Age and escalated in the early Middle Ages and Modern Times. The deposition of products of soil erosion was limited to between ca. 1.9-1.2 kyr BP, probably due to demographic regression during the Migration Period. Comparison of OM/MM fluctuations with phases of increased fluvial activity does not show a relationship between Holocene wetter phases and catchment sediment yield

  15. Mode of existence and seasonality of midge larvae (Diptera: Chironomidae) in man-made lakes in the Coachella Valley, southern California.

    PubMed

    Lothrop, B B; Mulla, M S

    1995-03-01

    Over the past 2 decades, numerous man-made ponds and lakes constructed in country clubs and on golf courses in the Coachella Valley have become ideal habitats for various chironomid species. Large numbers of adult midges emerging from these water bodies pose nuisance and economic problems. During 1992 and 1993 we initiated comprehensive studies on the nature and scope of the nuisance midge problem in the valley. We sampled on a biweekly basis 2 lakes supplied with well water, 2 supplied with tertiary effluent water, and one supplied with a mixture of these 2 sources, to determine the midge larval fauna and the mode of existence, seasonal abundance, and population trends of these midges. Climbers, clingers, portable sand tube builders, and tube builders on plants predominated in well-water habitats with submerged vegetation and detritus bottoms. Tube builders and burrowers predominated in the tertiary water, which characteristically had a detritus bottom, devoid of vegetation. Habitats holding a mixture of the 2 water types with sandy bottoms supported midge larvae known to be sprawlers.

  16. A note on the correlation between geophysical observations and seismicity in the Arava/(Araba) Valley at the southern part of the Dead Sea fault

    USGS Publications Warehouse

    Rybakov, M.; Shapira, A.; Al-Zoubi, A.; ten Brink, U.; Hofstetter, R.; Kraeva, N.; Feldman, L.

    2006-01-01

    The spatial distribution of the earthquakes in the Arava Valley, a 150-km section of the Dead Sea Transform, is compared for the first time with the local subsurface geological features derived from geophysical and geological data. Gravity data suggested that the Gharandal, Timna, and Elat basins were filled by low-density young sediments. These features were confirmed by seismic reflection profiles and high-resolution aeromagnetic (HRAM) survey. The HRAM survey delineated the trace of the Dead Sea Transform (DST), which separates magnetic anomalies in the eastern and western parts of the valley, and revealed the occurrence of the unknown deep magmatics. Overall, the earthquake activity appears to be strongly related to the Dead Sea Transform. However, on a local scale, there is no apparent correlation between the seismicity and the mapped fault segments comprising the DST fault system. Absence of the correlation may be a result of insufficient accuracy of the earthquake localization and/or the inclined fault plane. However, in spite of such inaccuracy, it is clearly observed that the large clusters of the low-magnitude earthquakes coincide well with the sedimentary basins. Two pronounced clusters appear to coincide with the subsurface magmatics. We assume that the subsurface geology predetermines areas of stress accumulation and earthquakes. These areas can be the end of faults, or fault jogs, which sometimes create basins. Magmatism can also be affected by the stress field and predetermine the stress and earthquakes' allocation. ?? 2007 Science From Israel/LPPLtd.

  17. Valley Floor

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-529, 30 October 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the floor of an ancient valley located near the Pyrrhae Chaos region of Mars. This valley might have been carved by liquid water, but today no evidence remains that a fluid ever flowed through it. Long after the valley formed, its floor was covered by large, windblown, ripple-like dunes. This picture is located near 13.0oS, 31.2oW. The image is illuminated by sunlight from the upper left and covers an area 3 km (1.9 mi) wide.

  18. Landscape ecology of arboviruses in southern California: patterns in the epizootic dissemination of western equine encephalomyelitis and St. Louis encephalitis viruses in Coachella Valley, 1991-1992.

    PubMed

    Reisen, W K; Hardy, J L; Lothrop, H D

    1995-05-01

    Temporal and spatial patterns in the initiation and dissemination of western equine encephalomyelitis and St. Louis encephalitis virus activity in Coachella Valley during 1991 and 1992 were detected by testing pools of host-seeking Culex tarsalis Coquillett for virus infection and sentinel chickens for seroconversions. Both viruses repeatedly were detected first at a salt marsh adjacent to the Salton Sea in the southeastern corner of the study area and then disseminated to the northwest to freshwater marsh, agricultural, and residential habitats. Virus dissemination was relatively slow (< 1 km/d) and may have been accomplished by dispersive host-seeking mosquitoes. Repeated early-season recovery of virus activity indicated that both viruses may persist interseasonally in salt marsh habitat. PMID:7616516

  19. Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front

    USGS Publications Warehouse

    Sohn, M.F.; Mahan, S.A.; Knott, J.R.; Bowman, D.D.

    2007-01-01

    Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been the subjects of study, but their ages have generally eluded researchers until recently. Most mapping efforts have recognized at least four major relative-age groupings (Q1 (oldest), Q2, Q3, and Q4 (youngest)), using observed changes in surface soils and morphology, relation to the drainage net, and development of desert pavement. Obtaining numerical age determinations for these morphologic stages has proven challenging. We report the first optically stimulated luminescence (OSL) ages for three of these four stages deposited within alluvial-fans along the tectonically active Black Mountains of Death Valley. Deposits showing distinct, remnant bar and swale topography (Q3b) have OSL ages from 7 to 4 ka., whereas those with moderate to poorly developed desert pavement and located farther above the active channel (Q3a) have OSL ages from 17 to 11 ka. Geomorphically older deposits with well-developed desert pavement (Q2d) have OSL ages ???25 ka. Using this OSL-based chronology, we note that alluvial-fan deposition along this tectonically active mountain front corresponds to both wet-to-dry and dry-to-wet climate changes recorded globally and regionally. These findings underscore the influence of climate change on alluvial fan deposition in arid and semi-arid regions. ?? 2007 Elsevier Ltd and INQUA.

  20. Constraints on Shallow Crustal Structure across the San Andreas Fault Zone, Coachella Valley, Southern California: Results from the Salton Seismic Imaging Project (SSIP)

    NASA Astrophysics Data System (ADS)

    Hernandez, A.; Persaud, P.; Bauer, K.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.

    2015-12-01

    The strong influence of basin structure and crustal heterogeneities on seismic wave propagation suggests that these factors should be included in calculations of strong ground shaking. Knowledge of the shallow subsurface is thus essential for an accurate seismic hazard estimate for the densely populated Coachella Valley, the region north of the potential M7.8 rupture near the Salton Sea. Using SSIP data, we analyzed first arrivals from nine 65-911 kg explosive shots recorded along a profile in the Coachella Valley in order to evaluate the interpretation of our 2D tomographic results and give added details on the structural complexity of the shallow crust. The line extends 37 km from the Peninsular Ranges to the Little San Bernardino Mountains crossing the major strands of the San Andreas Fault Zone. We fit traveltime curves to our picks with forward modeling ray tracing, and determined 1D P-wave velocity models for traveltime arrivals east and west of each shot, and a 2D model for the line. We also inferred the geometry of near-vertical faults from the pre-stack line migration method of Bauer et al. (2013). In general, the 1D models east of individual shots have deeper basement contacts and lower apparent velocities, ~5 km/s at 4 km depth, whereas the models west of individual shots have shallower basement and velocities up to 6 km/s at 2 km depth. Mismatches in basement depths (assuming 5-6 km/s) between individual 1D models indicate a shallowly dipping basement, deepening eastward towards the Banning Fault and shoaling abruptly farther east. An east-dipping structure in the 2D model also gives a better fit than horizontal layers. Based on high velocity zones derived from traveltimes at 9-20 km from the western end of the line, we included an offset from ~2 km to 4 km depth near the middle of the line, which significantly improved the 2D model fit. If fault-related, this offset could represent the Garnet Hill Fault if it continues southward in the subsurface.

  1. Geochemical tracing of As pollution in the Orbiel Valley (southern France): 87Sr/86Sr as a tracer of the anthropogenic arsenic in surface and groundwater.

    NASA Astrophysics Data System (ADS)

    Khaska, Mahmoud; Le Gal La Salle, Corinnne; Lancelot, Joël; Verdoux, Patrick; Boutin, René

    2014-05-01

    The environmental impacts of arsenic mining activities and their effects on ecosystem and human health are observed in many stream waters and groundwater. The aim of this study is to identify the origin of As content in a mining environment using Sr isotopes. At the Salsigne gold mine, before the closure in 2004, high arsenic content has been observed in surface water and groundwater in the Orbiel valley. At the site, immobilization of As, in As rich leachate, is carried out by adding CaO. High contrast in 87Sr/86Sr between Arsenic rich minerals associated with Variscan metamorphic rocks (0.714888-0.718835), together with rich As waste water (0.713463-715477), and the CaO (0.707593) allows as to trace the origin of anthropogenic As. In 2012, Orbiel stream waters were sampled monthly upstream and downstream from the ancient ore processing site and once after an important rainy event (117mm). The upstream valley samples showed low and relatively constant As content with natural regional background of 3.6 and 5.6 μg/L. The rainy event induced only a slight increase in the As content up to 6.3 μg/L. High 87Sr/86Sr ratios suggested an influence of radiogenic Sr issued from the Variscan metamorphic basement. Downstream from the area, the As content was at least10 time as high. In the wet season, stream water As content clearly increased to 13.9-24 μg/L, reaching 120.5 μg/L during the rainy event. Associated 87Sr/86Sr ratio showed to be less radiogenic (0.712276-0.714002). The anti correlation observed between As and 87Sr/86Sr suggest that As issued from a natural origin is characterised by a high 87Sr/86Sr compared to As derived from the CaO treatement used on site and characterized by a low 87Sr/86Sr ratio. During the dry season, increase in As content was observed reaching 110 μg/L. These highlights the contribution of alluvial groundwater to base flow, probably associated with As reach leachate from the site. Contribution from the alluvial aquifer is confirmed by

  2. Deep structure in the region of the San Fernando and Santa Clarita Valleys, southern California, from LARSE II seismic imaging, earthquake relocation, and magnetic modeling -- a progress report

    NASA Astrophysics Data System (ADS)

    Fuis, G. S.; Ryberg, T.; Lutter, W. J.; Hauksson, E.; Richards-Dinger, K. B.; Hildenbrand, T. G.; Langenheim, V. E.; Murphy, J. M.; Okaya, D. A.

    2001-12-01

    The Los Angeles Region Seismic Experiment has as its chief goal seismic imaging of sedimentary basins and faults in the Los Angeles region in order to address earthquake hazards posed by these geologic features. Two 150-km-long transects were investigated, one (LARSE I) crossing the Los Angeles basin and San Gabriel Mts in a northeasterly direction through the vicinity of the 1987 M 5.9 Whittier Narrows earthquake, and a second (LARSE II) crossing the San Fernando Valley (SFV) and Santa Clarita Valley (SCV) in a northerly direction through the vicinities of the 1994 M 6.7 Northridge and 1971 M 6.7 San Fernando earthquakes. Along the LARSE II profile, seismic reflection data and relocated earthquakes suggest that the Northridge fault is a relatively simple plane dipping ~30o southward from ~8 km depth beneath the Santa Susana Mts (between the SFV and SCV) to the 1994 hypocenter at ~19 km depth. Relocated hypocenters suggest a deep part of the Santa Susana fault was activated during the Northridge aftershock sequence. In contrast, the 1971 San Fernando earthquake appears to have activated several faults in addition to the two rupture planes inferred by Heaton (1982), including the Northridge Hills blind thrust fault and a deep part of the San Gabriel fault. These two faults truncate reflections from the bottoms of the sedimentary basins in the SFV and SCV. We interpret the Northridge Hills blind thrust fault to truncate basin-bottom reflections beneath the SFV at ~5-6 km depth in the northern part of the SFV, and the San Gabriel fault to truncate similar reflections at ~3.5-4.5 km depth beneath the central part of the SCV. The San Gabriel fault projects to the 1971 hypocenter. In between the Northridge Hills blind thrust and San Gabriel faults, reflections are largely incoherent, and the velocity structure is complex. Below the 1971 hypocenter (at ~13 km depth), the San Fernando fault appears to be contained in a broad north-dipping zone of reflectivity in which

  3. Landscape ecology of arboviruses in southern California: temporal and spatial patterns of vector and virus activity in Coachella Valley, 1990-1992.

    PubMed

    Reisen, W K; Lothrop, H D; Presser, S B; Milby, M M; Hardy, J L; Wargo, M J; Emmons, R W

    1995-05-01

    Consistent temporal and spatial patterns in the activity of Culex tarsalis Coquillett and western equine encephalomyelitis (WEE) and St. Louis encephalitis (SLE) viruses were delineated that were useful in developing a stratified surveillance program. Vernal increases in Cx. tarsalis abundance typically were associated with flooding of saline marshes along the north shore of the Salton Sea and were followed 6-8 wk later by the onset of WEE and SLE virus activity. Viruses then spread to managed marsh (duck club) and agricultural habitats in the Whitewater Channel flood plain and, depending upon the intensity of amplification, to agricultural and residential areas in the more elevated northwestern portion of the valley. Mean annual Cx. tarsalis abundance was correlated inversely with elevation and distance from the Salton Sea. Abundance was greatest at managed marsh habitats. Although spatially correlated with vector abundance among sites, virus transmission rates to sentinel chickens were asynchronous temporally with vector abundance. Seroconversion rates were related to flock location but not flock size (10 versus 20 chickens). Human cases were not detected during the study period, despite elevated transmission rates of both WEE and SLE viruses to sentinel chickens positioned in peridomestic habitats. PMID:7616515

  4. Landscape ecology of arboviruses in southern California: temporal and spatial patterns of vector and virus activity in Coachella Valley, 1990-1992.

    PubMed

    Reisen, W K; Lothrop, H D; Presser, S B; Milby, M M; Hardy, J L; Wargo, M J; Emmons, R W

    1995-05-01

    Consistent temporal and spatial patterns in the activity of Culex tarsalis Coquillett and western equine encephalomyelitis (WEE) and St. Louis encephalitis (SLE) viruses were delineated that were useful in developing a stratified surveillance program. Vernal increases in Cx. tarsalis abundance typically were associated with flooding of saline marshes along the north shore of the Salton Sea and were followed 6-8 wk later by the onset of WEE and SLE virus activity. Viruses then spread to managed marsh (duck club) and agricultural habitats in the Whitewater Channel flood plain and, depending upon the intensity of amplification, to agricultural and residential areas in the more elevated northwestern portion of the valley. Mean annual Cx. tarsalis abundance was correlated inversely with elevation and distance from the Salton Sea. Abundance was greatest at managed marsh habitats. Although spatially correlated with vector abundance among sites, virus transmission rates to sentinel chickens were asynchronous temporally with vector abundance. Seroconversion rates were related to flock location but not flock size (10 versus 20 chickens). Human cases were not detected during the study period, despite elevated transmission rates of both WEE and SLE viruses to sentinel chickens positioned in peridomestic habitats.

  5. Is it working? A look at the changing nutrient practices in the Southern Willamette Valley’s Groundwater Management Area

    EPA Science Inventory

    Groundwater nitrate contamination affects thousands of households in the southern Willamette Valley and many more across the Pacific Northwest. The southern Willamette Valley Groundwater Management Area (SWV GWMA) was established in 2004 to address the occurrence of high groundw...

  6. Lithologic properties of carbonate-rock aquifers at five test wells in the Coyote Spring Valley Area, southern Nevada, as determined from geophysical logs. Water resources investigation report

    SciTech Connect

    Berger, D.L.

    1992-01-01

    Regional ground-water flow systems in the carbonate-rock aquifers in southern Nevada were evaluated as potential sources for water supply as part of the Nevada Carbonate Aquifers Program. Geophysical log analyses indicated that the test wells penetrate carbonate rocks, which vary in composition from limestone to dolomite and include mixtures of both. Calcite was found to be the predominant matrix mineral and shales made up of only a small percentage of the overall rock. Bulk-density measurements averaged 2.65 grams per cubic centimeter and the matrix density estimates averaged 2.76 grams per cubic centimeter. Increased amounts of silica in the matrix mineralogy were associated with greater total porosity values. The log analyses indicated an average of 4.7 percent porosity for 43 zones in the test wells.

  7. Impact of tsetse and trypanosomiasis control on cattle herd composition and calf growth and mortality at Arbaminch District (Southern Rift Valley, Ethiopia).

    PubMed

    Gechere, Geja; Terefe, Getachew; Belihu, Kelay

    2012-10-01

    The effect of tsetse/trypanosomiasis control on cattle herd composition and growth and mortality of calves in tsetse controlled (by Southern Tsetse Eradication Project (STEP)) and uncontrolled blocks in southern Ethiopia was assessed. Structured questionnaire was used to interview 182 households to estimate cattle herd composition and calf mortality. Calves were bled to examine the presence of trypanosomes by the buffy coat technique. Forty NGU traps were deployed and fly catches determined. A case-control study was performed on 40 calves for 6 months to estimate calve growth parameters. Accordingly, the mean cattle herd size was lower in tsetse-controlled block than in the uncontrolled block, whereas the relative number of calves in a herd tend to be higher in the tsetse-controlled block (P = 0.06). While there was no report of cattle mortality in tsetse-controlled block, 16.48 % of the respondents have lost calves in tsetse-uncontrolled block in 1 year time. The prevalence of trypanosome positive calves was 2.95 % for uncontrolled block but no positive case in tsetse-controlled block. The apparent densities of flies/trap/day in tsetse-uncontrolled block were 30-fold higher than in tsetse-controlled block (P < 0.01). The case-control study revealed that the mean body weight gain of calves in tsetse-controlled block (40.23 ± 0.7 kg) was significantly higher than that of the uncontrolled block (34.74 ± 0.68 kg). The above findings strongly suggest that the intervention by the STEP project has significantly reduced tsetse population and trypanosomiasis consequently contributing to improved calf growth and survival.

  8. A 200,000-year record of late Quaternary Aeolian sedimentation on the Southern High Plains and nearby Pecos River Valley, USA

    NASA Astrophysics Data System (ADS)

    Rich, J.; Stokes, S.

    2011-03-01

    Presently stabilized Southern High Plains (SHP) dune systems have been repeatedly re-activated during the past 200,000 years, providing an archive of environmental and related climatic change for the late Quaternary. Our data set of 38 optically dated samples from four different localities identifies eolian activity from late-middle Pleistocene to the historic period. Oldest eolian sediments are from the Blackwater Draw Formation and indicate accretion during late-middle to late Pleistocene. Younger sediments dating from the later Pleistocene through the Holocene are found in the Muleshoe, Lea-Yoakum, Mescalero, and Monahans dunes that overlie the Blackwater Draw Formation. Muleshoe dunes accreted during the Late Pleistocene between 31 ± 3 and 27 ± 2 ka, while Holocene deposition transpired 7.5 ± 0.4, 4.0 ± 0.7 ka through 3.6 ± 0.4 ka, and between 1.3 ± 0.2 and 1.1 ± 0.1 ka. A period of dune building for Lea-Yoakum dune sediments occurred during the late Pleistocene (48 ± 5 ka), and the later Holocene (3.6 ± 0.4 ka). Mescalero and Monahans dunes were accreting during the later Pleistocene between 29 ± 3 and 22 ± 2 ka followed by a sequence of eolian sand deposited ca. 15 ka. Holocene eolian sedimentation for the Mescalero and Monahans dunes occurred 7.5 ± 0.8, 5.1 ± 0.5, 4.3 ± 0.4, and 2.0 ± 0.3 ka. Historic eolian deposition is identifiable in the dune chronology with multiple optical age estimates overlapping established drought events recorded ca. 1890, 1910, 1920, and during the 1930's when the North American "Dust Bowl" transpired. These Quaternary eolian deposits mantling the Southern High Plains are an important component of the surficial material of the region and provide a rich archive of past climatic change.

  9. Physical and institutional vulnerability assessment method applied in Alpine communities. Preliminary Results of the SAMCO-ANR Project in the Guil Valley (French Southern Alps)

    NASA Astrophysics Data System (ADS)

    Carlier, Benoit; Dujarric, Constance; Puissant, Anne; Lissak, Candide; Viel, Vincent; Bétard, François; Madelin, Malika; Fort, Monique; Arnaud-Fassetta, Gilles

    2015-04-01

    The Guil catchment is particularly prone to torrential and gravitational hazards such as floods, debris flows, landslides or avalanches due to several predisposing factors (bedrock supplying abundant debris, strong hillslope-channel connectivity) in a context of summer Mediterranean rainstorms as triggers. These hazards severely impact the local population (fatalities, destruction of buildings and infrastructures, loss of agricultural land, road closures). Since the second half of the 20th century, the progressive decline of agro-pastoralism and the development of tourism activities led to a concentration of human stakes on alluvial cones and valley bottom, therefore an increase of vulnerability for mountainous communities. Following the 1957 and 2000 catastrophic floods and the 1948 and 2008 avalanche episodes, some measures were taken to reduce exposure to risks (engineering works, standards of construction, rescue training…). Nevertheless, in front of urban expansion (land pressures and political pressures) and obsolescence of the existing protective measures, it is essential to reassess the vulnerability of the stakes exposed to hazards. Vulnerability analysis is, together with hazard evaluation, one of the major steps of risk assessment. In the frame of the SAMCO project designed for mountain risk assessment, our goal is to estimate specific form of vulnerability for communities living in the Upper Guil catchment in order to provide useful documentation for a better management of the valley bottom and the implementation of adequate mitigation measures. Here we present preliminary results on three municipalities of the upper Guil catchment: Aiguilles, Abriès, and Ristolas. We propose an empirical semi-quantitative indicator of potential hazards consequences on element at risk (based on GIS) with an application to different (local and regional scale) scales. This indicator, called Potential Damage Index, enable us to describe, quantify, and visualize direct

  10. PM1 geochemical and mineralogical characterization using SEM-EDX to identify particle origin - Agri Valley pilot area (Basilicata, Southern Italy)

    NASA Astrophysics Data System (ADS)

    Margiotta, S.; Lettino, A.; Speranza, A.; Summa, V.

    2015-01-01

    A PM1 geochemical and mineralogical study using Scanning Electron Microscopy (SEM) was performed on a pilot site in the Agri Valley which is close to the oil pre-treatment plant (C.O.V.A) of the Europe's largest on-shore hydrocarbon reservoir. The study identified PM1 geochemical and mineralogical characters in a period before, during and immediately after a burning torch flare event. The finer fraction (DFe < 0.7 μm) consisted mainly of secondary particles and soot. In the coarser fraction (DFe ≥ 0.7 μm), natural particles originating from crustal erosion and soot were abundant. Fine quartz particles and lower Al/Si ratios are markers for desert dust origin, proving that a Saharan dust episode which occurred during the observation period played a significant role in supplying geogenic aerosol components to the PM1. Largest amounts of ≥0.7 μm fraction particles observed on the day of flare event may be due to a greater supply of Saharan geogenic particles. Soot had been significantly increasing long before the flare event, suggesting that this increase is also related to other causes, although we cannot exclude a contribution from flaring. S-rich aerosol consisted mainly of mixed particles originating from deposition and heterogeneous nucleation of secondary sulfates on mineral dust. Only-S particles were identified in the ≥0.7 μm fraction following the flare event. These particles may be indicators of larger amounts of sulphur in the atmosphere.

  11. PM1 geochemical and mineralogical characterization using SEM-EDX to identify particle origin - Agri Valley pilot area (Basilicata, southern Italy)

    NASA Astrophysics Data System (ADS)

    Margiotta, S.; Lettino, A.; Speranza, A.; Summa, V.

    2015-07-01

    A PM1 geochemical and mineralogical study using Scanning Electron Microscopy (SEM) was performed on a pilot site in the Agri Valley which is close to the oil pre-treatment plant (C.O.V.A) of Europe's largest on-shore hydrocarbon reservoir. The study identified PM1 geochemical and mineralogical characters in the period before, during and immediately after a burning torch flare event. The finer fraction (DFe < 0.7 μm) consisted mainly of secondary particles and soot. In the coarser fraction (DFe ≥ 0.7 μm), natural particles originating from crustal erosion and soot were abundant. Fine quartz particles and lower Al / Si ratios are markers for desert dust origin, proving that a Saharan dust episode which occurred during the observation period played a significant role in supplying geogenic aerosol components to the PM1. Largest amounts of ≥ 0.7 μm fraction particles observed on the day of flare event may be due to a greater supply of Saharan geogenic particles. Soot had been significantly increasing long before the flare event, suggesting that this increase is also related to other causes, although we cannot exclude a contribution from flaring. S-rich aerosol consisted mainly of mixed particles originating from deposition and heterogeneous nucleation of secondary sulfates on mineral dust. Only-S particles were identified in the ≥ 0.7 μm fraction following the flare event. These particles may be indicators of larger amounts of sulphur in the atmosphere.

  12. The geochemistry and isotope hydrology of the Southern Mexicali Valley in the area of the Cerro Prieto, Baja California (Mexico) geothermal field

    NASA Astrophysics Data System (ADS)

    Portugal, Enrique; Izquierdo, Georgina; Truesdell, Alfred; Álvarez, Julio

    2005-11-01

    Groundwaters from the phreatic aquifer within and surrounding of the Cerro Prieto geothermal field were analyzed geochemically and isotopically in order to establish a hydrodynamic model of the study zone, which is located in the Mexicali Valley between 655,000-685,000 m E-W and 3,605,000-3,576,000 m N-S relative to UTM coordinates. Based on their chemical composition three types of water were recognized: chloride, sulfate and bicarbonate. However four groups of water were identified on a statistical multi-variable method of cluster analysis (A-D). The average temperature is 25 °C; with a few exceptions in the south where temperature can be as high as 47 °C. Stable isotope ratios for some waters plot close to the world meteoric line, corresponding to the original unaltered waters of the zone. The hydrogeochemistry varies in relation to three principal processes: evaporation, infiltration of water used in agriculture and rock interaction by reaction with evaporitic deposits. Major quartz, calcite and plagioclase and minor smectite, kaolinite, halite, sylvite and gypsum were identified by X-ray diffraction in lacustrine sediments of the central part of the zone. Chemical modeling indicates saturation with respect to calcite and undersaturation with respect to gypsum. By incorporating chemical and isotope data into geological and isopotential well information, a hydrodynamic model has been postulated. In this hydrodynamic model the water (A) enters the study zone from the east and it is originally of the old Colorado River water. The water samples on which the model is based were draw from agricultural wells that intersected two aquifers, a shallow and a deep one, representing the recharge to the zone. The salinity of the deep aquifer water (B) is lower than that of the shallow aquifer water (C) and so is the stable isotope ratio. The difference is though to be due to dissolution of evaporates, evaporation and possible infiltration of spent agriculture water. Both

  13. Hypothesis on the origin of lineaments in the LANDSAT and SLAR images of precambrian soil in the low Contas River Valley (southern Bahia)

    NASA Technical Reports Server (NTRS)

    Liu, C. C. (Principal Investigator); Rodrigues, J. E.

    1984-01-01

    Examination of LANDSAT and SLAR images in southern Bahia reveals numerous linear features, which are grouped in five sets, based on their trends: N65 degrees E, N70 degrees W, N45 degrees E and NS/N15 degrees E. Owing to their topographic expressions, distributive patterns, spacing between individual lineaments and their mutual relationships, the lineament sets of N65 degrees E and N70 degrees W, as well as the sets of N40 degrees E and N45 degrees W, are considered as two groups of conjugate shear fractures and the former is older and is always cut by the latter. Their conjugate shear angles are 45 degrees and 85 degrees and their bisector lines are approximately in east-west and north-south directions, respectively. According to Badgeley's argumentation on the conjugate shear angles, the former conjugate shear fractures would be caused by: (1) vertical movements, and the bisector of their conjugate angle would be parallel to the long axis of horsting or folding, or (2) by a compressive force in the east-west direction and under a condition of low confining pressure and temperature.

  14. Further Resolution of Past Earthquake Surface Ruptures at the Carrizo Wash Site, Superstition Mountain Strand of the San Jacinto Fault, Imperial Valley, Southern California.

    NASA Astrophysics Data System (ADS)

    Verdugo, D.; Ragona, D. E.; Rockwell, T. K.

    2005-12-01

    We present results from new trench exposures in Carrizo Wash along the northernmost part of the Superstition Mountain strand (SMF) of the San Jacinto Fault, southern California. Prior paleoseismic work by Ragona (2003) recovered evidence for 7 earthquake events, 3 of which occurred in the past 1000 years. The most recent event produced only 15 cm of slip and is only recognized along the Coyote Creek Fault (CCF). The other two recognized events cumulatively produced nearly 6 m of slip. However, an erosional unconformity in the initial excavations removed evidence for at least one event, based on problematic correlations to nearby sites resulting from mismatches in both the number of recognized lake units as well as the relative stratigraphic position of events with respect to the lakes. The new trenches, south of the effects of the erosional channel, contain evidence for an additional event and an additional delta-lake sequence not present in the original exposures. The new event likely correlates to the penultimate event at the Northern Shoreline site (Gurrola and Rockwell, 1996). Thus, the observed 6 m of slip was mostly accommodated by three events, suggesting about 2 m of slip per event for large SMF ruptures. Our new observations also agree well with data from four other nearby trench sites along the CCF and SMF, and suggest that 1) the SMF has ruptured in only three large events in the past 1100 years, 2) at least two of these events are likely recognized along the CCF, indicating that the step-over between SMF and CCF is soft in large events, 3) most CCF ruptures do not propagate onto the SMF, indicating that the step-over is hard for small displacements, such as 1968-type events (30-50 cm of slip). These observations support the concept of segmentation but indicate that a perceived segment boundary may be transparent if slip exceeds a threshold value.

  15. Physical, social and institutional vulnerability assessment in small Alpine communities. Results of the SAMCO-ANR project in the Upper Guil Valley (French Southern Alps)

    NASA Astrophysics Data System (ADS)

    Carlier, Benoit; Dujarric, Constance; Frison-Bruno, Nikita; Puissant, Anne; Lissak, Candide; Madelin, Malika; Viel, Vincent; Bétard, François; Fort, Monique; Arnaud-Fassetta, Gilles

    2016-04-01

    The Upper Guil catchment is particularly prone to hydromorphological hazards such as torrential floods, debris flows, landslides or avalanches. Following the catastrophic events of the last 60 years (1957, 1978, 2000, and 2008), some measures were taken to reduce exposure to risks (engineering works, standards of construction, rescue training…). Nevertheless, the development of urban settlement in endangered areas and the obsolescence of the existing protective measures revealed the necessity to reassess the vulnerability of the different stakes exposed to hazards and to take into account of these various component parts of the vulnerability (not only physical but also social, etc.). In addition, catastrophic events should be more frequent in the French Southern Alps, according to the last GIEC report. In the frame of the SAMCO project designed for mountain risk assessment in a context of global change, we developed a systemic approach to assess three specific components of vulnerability - physical, social and institutional - for the six municipalities of the Upper Guil catchment (Ristolas, Abriès, Aiguilles, Château-Ville-Vieille, Molines-en-Queyras and St-Véran). Physical vulnerability, which represents total potential consequences of hazards on stakes, was estimated and mapped using a GIS model based on an empirical semi-quantitative indicator, the Potential Damage Index (PDI). This index allowed us to quantify and describe both direct (physical injury, structural and functional damage on buildings, network and land cover) and indirect consequences (socio-economic impacts) induced by hazards, by combining weighted parameters (age, state, material, function, etc.) reflecting the exposure of elements at risk. At least 1890 buildings, 367 km² of land cover and 902 km of linear infrastructure were considered. To assess social and institutional vulnerability our approach was based on questionnaires (5% of the total population investigated), interviews and

  16. Martian oceans, valleys and climate

    USGS Publications Warehouse

    Carr, M.H.

    2000-01-01

    The new Mars Global Surveyor altimetry shows that the heavily cratered southern hemisphere of Mars is 5 km higher that the sparely cratered plains of the northern hemisphere. Previous suggestions that oceans formerly occupied that northern plains as evidenced by shorelines are partly supported by the new data. A previously identified outer boundary has a wide range of elevations and is unlikely to be a shoreline but an inner contact with a narrow range of elevations is a more likely candidate. No shorelines are visible in the newly acquired, 2.5 metre/pixel imaging. Newly imaged valleys provide strong support for sustained or episodic flow of water across the Martian surface. A major surprise, however, is the near absence of valleys less than 100 m across. Martian valleys seemingly do not divide into ever smaller valleys as terrestrial valleys commonly do. This could be due to lack of precipitation or lack of surface runoff because of high infiltration rates. High erosion rates and supports warm climates and presence of large bodies of water during heavy bombardment. The climate history and fate of the water after heavy bombardment remain cotroversial.

  17. TDRS satellite over African Rift Valley, Kenya, Africa

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This post deploy view of a TDRS satellite shows a segment of the African Rift Valley near Lake Baringo, Kenya, Africa (3.0S, 36.0E). The African Rift Valley system is a geologic fault having its origins in southern Turkey, through the near east forming the bed of the Jordan River, Gulf of Aqaba, the Red Sea and down through east Africa. The line of lakes and valleys of east Africa are the result of the faulting activity.

  18. Ohio Valley Community Health Information Network.

    ERIC Educational Resources Information Center

    Guard, Roger; And Others

    The Ohio Valley Community Health Information Network (OVCHIN) works to determine the efficacy of delivering health information to residents of rural southern Ohio and the urban and suburban Cincinnati area. OVCHIN is a community-based, consumer-defined demonstration grant program funded by the National Telecommunications and Information…

  19. Cosmogenic Nuclides 10Be-21Ne Burial Dating of Middle Miocene Sedimentary Formation of the Hongliu Valley in Southern Ningxia Basin: A Case of Isotopic Geochronology Study for the Cenozoic Sedimentary Strata

    NASA Astrophysics Data System (ADS)

    Ma, Yan; Zhang, Huiping; Wang, Weitao; Pang, Jianzhang; Zheng, Dewen

    2016-04-01

    Chronology studies for the Cenozoic sedimentary strata based on the magnetostratigraphy cannot afford the unique chronological sequences in the absence of absolute ages from biostratigraphy or volcanic ash chronology. In situ-produced cosmogenic nuclides provide a powerful tool for the sediment dating based on the time-dependent concentration ratio of two nuclides, which are produced in the same mineral but with different half-lives. Thereinto,10Be-26Al is the most widely used nuclide pairs, of which the available dating range spans the Plio-Pleistocene. But the coupling of 10Be with the stable nuclide 21Ne would significantly improve the burial dating range up to the middle Miocene, which is promising in revolutionizing the chronology study for the Late Cenozoic terrestrial sedimentary sequences. We have applied 10Be-21Ne pair for dating the middle Miocene sediments of the Hongliu Valley in southern Ningxia basin. Two major features of the sediments are involved in our study: (1) sediments originated from the steady erosion of the source area, and (2) the burial depth of our sample after deposition is time dependent due to the gradual accumulation of sediments into basin. The post-burial nuclide production is estimated to be less than 3%, including the contribution by muon interactions, of the total nuclide concentrations measured in our sample. Our 10Be-21Ne analysis demonstrates the age of the burial sample is 12.4(+0.6/-0.4) Ma, and the erosion rate at the source area is 0.26±0.01 cm ka-1. The sample's burial age is consistent with the age constraint set by the Hongliugou Formation (16.7-5.4 Ma) which we collected the sample in. Vertebrate fossils of Platybelodon tongxinensis with an age between 12 and 15 Ma exhumated along with our sample further verifies the reliability of our dating results for the middle Miocene sediments.This study has shown the improved age range of cosmogenic-nuclide burial dating method by incorporating the stable nuclide 21Ne, and has

  20. Valley Divide

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03664 Valley Divide

    These small channels join to become Sabis Vallis.

    Image information: VIS instrument. Latitude -35.3N, Longitude 159.3E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  1. Saline Valley

    NASA Technical Reports Server (NTRS)

    2001-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1 Figure 2

    These images of the Saline Valley area, California, were acquired March 30, 2000 and cover a full ASTER scene (60 by 60 km). Each image displays data from a different spectral region, and illustrates the complementary nature of surface compositional information available as a function of wavelength. This image displays visible and near infrared bands 3, 2, and 1 in red, green, and blue (RGB). Vegetation appears red, snow and dry salt lakes are white, and exposed rocks are brown, gray, yellow and blue. Rock colors mainly reflect the presence of iron minerals, and variations in albedo. Figure 1 displays short wavelength infrared bands 4, 6, and 8 as RGB. In this wavelength region, clay, carbonate, and sulfate minerals have diagnostic absorption features, resulting in distinct colors on the image. For example, limestones are yellow-green, and purple areas are kaolinite-rich. Figure 2 displays thermal infrared bands 13, 12 and 10 as RGB. In this wavelength region, variations in quartz content appear as more or less red; carbonate rocks are green, and mafic volcanic rocks are purple. The image is located at 36.8 degrees north latitude and 117.7 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  2. A brief history of oil and gas exploration in the southern San Joaquin Valley of California: Chapter 3 in Petroleum systems and geologic assessment of oil and gas in the San Joaquin Basin Province, California

    USGS Publications Warehouse

    Takahashi, Kenneth I.; Gautier, Donald L.

    2007-01-01

    The Golden State got its nickname from the Sierra Nevada gold that lured so many miners and settlers to the West, but California has earned much more wealth from so-called “black gold” than from metallic gold. The San Joaquin Valley has been the principal source for most of the petroleum produced in the State during the past 145 years. In attempting to assess future additions to petroleum reserves in a mature province such as the San Joaquin Basin, it helps to be mindful of the history of resource development. In this chapter we present a brief overview of the long and colorful history of petroleum exploration and development in the San Joaquin Valley. This chapter relies heavily upon the work of William Rintoul, who wrote extensively on the history of oil and gas exploration in California and especially in the San Joaquin Valley. No report on the history of oil and gas exploration in the San Joaquin Valley would be possible without heavily referencing his publications. We also made use of publications by Susan Hodgson and a U.S. Geological Survey Web site, Natural Oil and Gas Seeps in California (http://seeps.wr.usgs.gov/seeps/index.html), for much of the material describing the use of petroleum by Native Americans in the San Joaquin Valley. Finally, we wish to acknowledge the contribution of Don Arnot, who manages the photograph collection at the West Kern Oil Museum in Taft, California. The collection consists of more than 10,000 photographs that have been scanned and preserved in digital form on CD-ROM. Many of the historical photographs used in this paper are from that collection. Finally, to clarify our terminology, we use the term “San Joaquin Valley” when we refer to the geographical or topographical feature and the term “San Joaquin Basin” when we refer to geological province and the rocks therein.

  3. Hydrogeologic framework and estimates of groundwater storage for the Hualapai Valley, Detrital Valley, and Sacramento Valley basins, Mohave County, Arizona

    USGS Publications Warehouse

    Truini, Margot; Beard, L. Sue; Kennedy, Jeffrey; Anning, Dave W.

    2013-01-01

    We have investigated the hydrogeology of the Hualapai Valley, Detrital Valley, and Sacramento Valley basins of Mohave County in northwestern Arizona to develop a better understanding of groundwater storage within the basin fill aquifers. In our investigation we used geologic maps, well-log data, and geophysical surveys to delineate the sedimentary textures and lithology of the basin fill. We used gravity data to construct a basin geometry model that defines smaller subbasins within the larger basins, and airborne transient-electromagnetic modeled results along with well-log lithology data to infer the subsurface distribution of basin fill within the subbasins. Hydrogeologic units (HGUs) are delineated within the subbasins on the basis of the inferred lithology of saturated basin fill. We used the extent and size of HGUs to estimate groundwater storage to depths of 400 meters (m) below land surface (bls). The basin geometry model for the Hualapai Valley basin consists of three subbasins: the Kingman, Hualapai, and southern Gregg subbasins. In the Kingman subbasin, which is estimated to be 1,200 m deep, saturated basin fill consists of a mixture of fine- to coarse-grained sedimentary deposits. The Hualapai subbasin, which is the largest of the subbasins, contains a thick halite body from about 400 m to about 4,300 m bls. Saturated basin fill overlying the salt body consists predominately of fine-grained older playa deposits. In the southern Gregg subbasin, which is estimated to be 1,400 m deep, saturated basin fill is interpreted to consist primarily of fine- to coarse-grained sedimentary deposits. Groundwater storage to 400 m bls in the Hualapai Valley basin is estimated to be 14.1 cubic kilometers (km3). The basin geometry model for the Detrital Valley basin consists of three subbasins: northern Detrital, central Detrital, and southern Detrital subbasins. The northern and central Detrital subbasins are characterized by a predominance of playa evaporite and fine

  4. Long Valley Observatory

    USGS Publications Warehouse

    Venezky, Dina Y.; Hill, David

    2008-01-01

    The ~300-year-old lava on Paoha Island in Mono Lake was produced by the most recent eruption in the Long Valley Caldera area in east-central California. The Long Valley Caldera was formed by a massive volcanic eruption 760,000 years ago. The region is monitored by the Long Valley Observatory (LVO), one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about the Long Valley Caldera region and LVO at http://volcanoes.usgs.gov/lvo.

  5. Subglacial extensional fracture development and implications for Alpine Valley evolution

    NASA Astrophysics Data System (ADS)

    Leith, Kerry; Moore, Jeffrey R.; Amann, Florian; Loew, Simon

    2014-01-01

    stresses induced through exhumation and tectonic processes play a key role in the topographic evolution of alpine valleys. Using a finite difference model combining the effects of tectonics, erosion, and long-term bedrock strength, we assess the development of near-surface in situ stresses and predict bedrock behavior in response to glacial erosion in an Alpine Valley (the Matter Valley, southern Switzerland). Initial stresses are derived from the regional tectonic history, which is characterized by ongoing transtensional or extensional strain throughout exhumation of the brittle crust. We find that bedrock stresses beneath glacial ice in an initial V-shaped topography are sufficient to induce localized extensional fracturing in a zone extending laterally 600 m from the valley axis. The limit of this zone is reflected in the landscape today by a valley "shoulder," separating linear upper mountain slopes from the deep U-shaped inner valley. We propose that this extensional fracture development enhanced glacial quarrying between the valley shoulder and axis and identify a positive feedback where enhanced quarrying promoted valley incision, which in turn increased in situ stress concentrations near the valley floor, assisting erosion and further driving rapid U-shaped valley development. During interglacial periods, these stresses were relieved through brittle strain or topographic modification, and without significant erosion to reach more highly stressed bedrock, subsequent glaciation caused a reduction in differential stress and suppressed extensional fracturing. A combination of stress relief during interglacial periods, and increased ice accumulation rates in highly incised valleys, will reduce the likelihood of repeat enhanced erosion events.

  6. Down in the Valley.

    ERIC Educational Resources Information Center

    Salter, Linda Graef

    1999-01-01

    Describes the partnerships formed by West Valley Mission Community College District (California) with its surrounding Silicon Valley business community in an effort to benefit workforce development. Asserts that community colleges are uniquely positioned to provide a lifelong education that will yield a skilled workforce to meet the needs of…

  7. Rift Valley Fever Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  8. California: San Joaquin Valley

    Atmospheric Science Data Center

    2014-05-15

    article title:  Fog and Haze in California's San Joaquin Valley   ... is noted for its hazy overcasts and a low, thick ground fog known as the Tule. Owing to the effects of the atmosphere on reflected ... as the angle of view changes. An area of thick, white fog in the San Joaquin Valley is visible in all three of the images. However, ...

  9. Ganges valley aerosol experiment.

    SciTech Connect

    Kotamarthi, V.R.; Satheesh, S.K.

    2011-08-01

    In June 2011, the Ganges Valley Aerosol Experiment (GVAX) began in the Ganges Valley region of India. The objective of this field campaign is to obtain measurements of clouds, precipitation, and complex aerosols to study their impact on cloud formation and monsoon activity in the region.

  10. Southern Appalachian Regional Seismic Network

    SciTech Connect

    Chiu, S.C.C.; Johnston, A.C.; Chiu, J.M.

    1994-08-01

    The seismic activity in the southern Appalachian area was monitored by the Southern Appalachian Regional Seismic Network (SARSN) since late 1979 by the Center for Earthquake Research and Information (CERI) at Memphis State University. This network provides good spatial coverage for earthquake locations especially in east Tennessee. The level of activity concentrates more heavily in the Valley and Ridge province of eastern Tennessee, as opposed to the Blue Ridge or Inner Piedmont. The large majority of these events lie between New York - Alabama lineament and the Clingman/Ocoee lineament, magnetic anomalies produced by deep-seated basement structures. Therefore SARSN, even with its wide station spacing, has been able to define the essential first-order seismological characteristics of the Southern Appalachian seismic zone. The focal depths of the southeastern U.S. earthquakes concentrate between 8 and 16 km, occurring principally beneath the Appalachian overthrust. In cross-sectional views, the average seismicity is shallower to the east beneath the Blue Ridge and Piedmont provinces and deeper to the west beneath the Valley and Ridge and the North American craton. Results of recent focal mechanism studies by using the CERI digital earthquake catalog between October, 1986 and December, 1991, indicate that the basement of the Valley and Ridge province is under a horizontal, NE-SW compressive stress. Right-lateral strike-slip faulting on nearly north-south fault planes is preferred because it agrees with the trend of the regional magnetic anomaly pattern.

  11. The First Prediction of a Rift Valley Fever Outbreak

    NASA Technical Reports Server (NTRS)

    Anyamba, Assaf; Chretien, Jean-Paul; Small, Jennifer; Tucker, Compton J.; Formenty, Pierre; Richardson, Jason H.; Britch, Seth C.; Schnabel, David C.; Erickson, Ralph L.; Linthicum, Kenneth J.

    2009-01-01

    El Nino/Southern Oscillation (ENSO) related anomalies were analyzed using a combination of satellite measurements of elevated sea surface temperatures, and subsequent elevated rainfall and satellite derived normalized difference vegetation index data. A Rift Valley fever risk mapping model using these climate data predicted areas where outbreaks of Rift Valley fever in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. This is the first prospective prediction of a Rift Valley fever outbreak.

  12. 14. ALABAMA, SUMTER CO., EPES RAILROAD BRIDGE Southern RR at ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. ALABAMA, SUMTER CO., EPES RAILROAD BRIDGE Southern RR at Epes Alabama Great Southern RR bridge. View from S. Copy of photo taken in 1922 by Jack Donnell, Columbus, Ms. Sarcone Photography, Columbus, Ms., Sep 1978. - Bridges of the Upper Tombigbee River Valley, Cochrane, Pickens County, AL

  13. Morphology of the Ebro fan valleys from SeaMARC and sea beam profiles

    USGS Publications Warehouse

    Alonso, B.; Kastens, K.A.; Maldonado, A.; Malinverno, A.; Nelson, C.H.; O'Connell, S.; Palanques, A.; Ryan, William B. F.

    1985-01-01

    The northern continental slope off the Ebro Delta has a badland topography indicating major slope erosion and mass movement of material that deposits sediment into a ponded lobe. The southern slope has a low degree of mass movement activity and slope valleys feed channel levee-complexes on a steep continental rise. The last active fan valley is V-shaped with little meandering and its thalweg merges downstream with the Valencia Valley. The older and larger inactive channel-levee complex is smoother, U-shaped, and meanders more than the active fan valley. ?? 1985 Springer-Verlag New York Inc.

  14. Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study

    SciTech Connect

    Sammel, E.A.; Craig, R.W.

    1981-01-01

    Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill dpeosits in these areas may be about 40/sup 0/C per kilometer. Geothermometers and mixing models indicate that temperatures of equilibration are at least 170/sup 0/C for the thermal components of the hotter waters. The size and location of geothermal reservoirs are unknown.

  15. Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study

    SciTech Connect

    Sammel, E.A.; Craig, R.W.

    1981-01-01

    Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. The warmer waters are likely to have higher concentrations of sodium and chloride, as well as sulfate, silica, and dissolved solids, than the cooler waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill deposits in these areas may be about 40/sup 0/C per kilometer. Extensive areas underlain by thermal ground water occur near Crump geyser and Fisher Hot Spring.

  16. Rift Valley Fever (RVF)

    MedlinePlus

    ... Outbreak resources, VHF information for specific groups, virus ecology, references... RVF Distribution Map Rift Valley Fever Transmission ... Outbreaks Outbreak Summaries RVF Distribution Map Resources Virus Ecology File Formats Help: How do I view different ...

  17. Ariel's transecting valleys

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This highest-resolution Voyager 2 view of Ariel's terminator shows a complex array of transecting valleys with super-imposed impact craters. Voyager obtained this clear-filter, narrow-angle view from a distance of 130,000 kilometers (80,000 miles) and with a resolution of about 2.4 km (1.5 mi). Particularly striking to Voyager scientists is the fact that the faults that bound the linear valleys are not visible where they transect one another across the valleys. Apparently these valleys were filled with deposits sometime after they were formed by tectonic processes, leaving them flat and smooth. Sinuous rilles (trenches) later formed, probably by some flow process. Some type of fluid flow may well have been involved in their evolution. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  18. California: Diamond Valley

    Atmospheric Science Data Center

    2014-05-15

    ... County is billed as the largest earthworks construction project in U.S. history. Construction began in 1995 and involved 31 million ... water storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against ...

  19. Lily of the valley

    MedlinePlus

    ... of the valley poisoning occurs when someone eats parts of this plant. This article is for information only. DO NOT ... information: Person's age, weight, and condition Name and part of the plant swallowed, if known Time it was swallowed Amount ...

  20. NV PFA - Steptoe Valley

    SciTech Connect

    Jim Faulds

    2015-10-29

    All datasets and products specific to the Steptoe Valley model area. Includes a packed ArcMap project (.mpk), individually zipped shapefiles, and a file geodatabase for the northern Steptoe Valley area; a GeoSoft Oasis montaj project containing GM-SYS 2D gravity profiles along the trace of our seismic reflection lines; a 3D model in EarthVision; spreadsheet of links to published maps; and spreadsheets of well data.

  1. Analysis of crater valleys, Noachis Terra, Mars: Evidence of fluvial and glacial processes

    NASA Astrophysics Data System (ADS)

    Hobbs, S. W.; Clarke, J. D. A.; Paull, D. J.

    2016-05-01

    The precise mechanism for the formation and evolution of crater valley networks in the Martian southern highlands remains under debate, with precipitation, groundwater flow, and melting induced by impact being suggested. We studied valley networks within four craters of the Noachis Terra highlands that were representative of similar features in Noachis Terra and where orbital data existed for analysis in order to characterise their morphology and infer possible processes involved in their formation and evolution. We found evidence for valleys carved by liquid water and ice-related processes. This included strong evidence of liquid water-based valley formation through melting of ice-rich deposits throughout our study area, suggesting an alternative to previously suggested rainfall or groundwater-based scenarios. The location of these valleys on steeply sloping crater walls, as opposed to the shallow slopes of the highlands where Martian valleys are typically found, suggested that our 'fluvial' valleys had not evolved a more structured fluvial morphology as valley networks found on the Martian plains. Our studied valleys' association with ice-rich material and abundant evidence for erosion caused by downslope flow of ice-rich material are consistent with a cold, wet Mars hypothesis where accumulation, flow, and melting of ice have been dominant factors in eroding crater valleys. Additionally, analysis of valley morphology with slope and aspect suggested a greater dependence on local geology and presence of volatiles than larger valley networks, though ice-related valleys were consistently wider for their length than valleys assessed as fluvial carved. We assessed that local conditions such as climate, geology, and availability of ice-rich material played a major role in the erosion of crater valleys at our study site.

  2. Grizzly Valley fault system, Sierra Valley, CA

    USGS Publications Warehouse

    Gold, Ryan; Stephenson, William; Odum, Jack; Briggs, Rich; Crone, Anthony; Angster, Steve

    2012-01-01

    The Grizzly Valley fault system (GVFS) strikes northwestward across Sierra Valley, California and is part of a network of active, dextral strike-slip faults in the northern Walker Lane (Figure 1). To investigate Quaternary motion across the GVFS, we analyzed high-resolution (0.25 m) airborne LiDAR data (Figure 2) in combination with six, high-resolution, P-wave, seismic-reflection profiles [Gold and others, 2012]. The 0.5- to 2.0-km-long seismic-reflection profiles were sited orthogonal to suspected tectonic lineaments identified from previous mapping and our analysis of airborne LiDAR data. To image the upper 400–700 m of subsurface stratigraphy of Sierra Valley (Figure 3), we used a 230-kg accelerated weight drop source. Geophone spacing ranged from 2 to 5 m and shots were co-located with the geophones. The profiles reveal a highly reflective, deformed basal marker that we interpret to be the top of Tertiary volcanic rocks, overlain by a 120- to 300-m-thick suite of subhorizontal reflectors we interpret as Plio-Pleistocene lacustrine deposits. Three profiles image the principle active trace of the GVFS, which is a steeply dipping fault zone that offsets the volcanic rocks and the basin fill (Figures 4 & 5).

  3. Earthquakes in Tuhinj Valley (Slovenia) In 1840

    NASA Astrophysics Data System (ADS)

    Cecić, Ina

    2015-04-01

    A less known damaging earthquake in southern part of Kamnik-Savinja Alps, Slovenia, in 1840 is described. The main shock was on 27 August 1840 with the epicentre in Tuhinj Valley. The maximum intensity was VII EMS-98 in Ljubljana, Slovenia, and in Eisenkappel, Austria. It was felt as far as Venice, Italy, 200 km away. The macroseismic magnitude of the main shock, estimated from the area of intensity VI EMS-98, was 5.0. The effects of the main shock and its aftershocks are described, and an earthquake catalogue for Slovenia in 1840 is provided. Available primary sources (newspaper articles) are presented.

  4. The geochemistry of groundwater resources in the Jordan Valley: The impact of the Rift Valley brines

    USGS Publications Warehouse

    Farber, E.; Vengosh, A.; Gavrieli, I.; Marie, A.; Bullen, T.D.; Mayer, B.; Polak, A.; Shavit, U.

    2007-01-01

    The chemical composition of groundwater in the Jordan Valley, along the section between the Sea of Galilee and the Dead Sea, is investigated in order to evaluate the origin of the groundwater resources and, in particular, to elucidate the role of deep brines on the chemical composition of the regional groundwater resources in the Jordan Valley. Samples were collected from shallow groundwater in research boreholes on two sites in the northern and southern parts of the Jordan Valley, adjacent to the Jordan River. Data is also compiled from previous published studies. Geochemical data (e.g., Br/Cl, Na/Cl and SO4/Cl ratios) and B, O, Sr and S isotopic compositions are used to define groundwater groups, to map their distribution in the Jordan valley, and to evaluate their origin. The combined geochemical tools enabled the delineation of three major sources of solutes that differentially affect the quality of groundwater in the Jordan Valley: (1) flow and mixing with hypersaline brines with high Br/Cl (>2 ?? 10-3) and low Na/Cl (<0.8) ratios; (2) dissolution of highly soluble salts (e.g., halite, gypsum) in the host sediments resulting in typically lower Br/Cl signal (<2 ?? 10-3); and (3) recharge of anthropogenic effluents, primarily derived from evaporated agricultural return flow that has interacted (e.g., base-exchange reactions) with the overlying soil. It is shown that shallow saline groundwaters influenced by brine mixing exhibit a north-south variation in their Br/Cl and Na/Cl ratios. This chemical trend was observed also in hypersaline brines in the Jordan valley, which suggests a local mixing process between the water bodies. ?? 2007 Elsevier Ltd. All rights reserved.

  5. New vectors of Rift Valley fever in West Africa.

    PubMed Central

    Fontenille, D.; Traore-Lamizana, M.; Diallo, M.; Thonnon, J.; Digoutte, J. P.; Zeller, H. G.

    1998-01-01

    After an outbreak of Rift Valley fever in Southern Mauritania in 1987, entomologic studies were conducted in a bordering region in Sénégal from 1991 to 1996 to identify the sylvatic vectors of Rift Valley fever virus. The virus was isolated from the floodwater mosquitoes Aedes vexans and Ae. ochraceus. In 1974 and 1983, the virus had been isolated from Ae. dalzieli. Although these vectors differ from the main vectors in East and South Africa, they use the same type of breeding sites and also feed on cattle and sheep. Although enzootic vectors have now been identified in West Africa, the factors causing outbreaks remain unclear. PMID:9621201

  6. Hydrogeology of the carbonate rocks of the Lebanon Valley, Pennsylvania

    USGS Publications Warehouse

    Meisler, Harold

    1963-01-01

    The Lebanon Valley, which is part of the Great Valley in southeastern Pennsylvania, is underlain by carbonate rocks in the southern part and by shale in the northern part. The carbonate rocks consist of alternating beds of limestone and dolomite of Cambrian and Ordovician age. Although the beds generally dip to the south, progressively younger beds crop out to the north, because the rocks are overturned. The stratigraphic units, from oldest to youngest, are: the Buffalo Springs Formation, Snitz Creek, Schaefferstown, Millbach, and Richland Formations of the Conococheague Group; the Stonehenge, Rickenbach, Epler, and Ontelaunee Formations of the Beekmantown Group; and the Annville, Myerstown, and Hershey Limestones.

  7. Diversity of micro-fungi in an Antarctic dry valley

    NASA Technical Reports Server (NTRS)

    Baublis, J. A.; Wharton, R. A. Jr; Volz, P. A.; Wharton RA, J. r. (Principal Investigator)

    1991-01-01

    The fungal microflora of a dry valley in Southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3 precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.

  8. Geohydrology of the Unconsolidated Valley-Fill Aquifer in the Meads Creek Valley, Schuyler and Steuben Counties, New York

    USGS Publications Warehouse

    Miller, Todd S.; Bugliosi, Edward F.; Reddy, James E.

    2008-01-01

    The Meads Creek valley encompasses 70 square miles of predominantly forested uplands in the upper Susquehanna River drainage basin. The valley, which was listed as a Priority Waterbody by the New York State Department of Environmental Conservation in 2004, is prone to periodic flooding, mostly in its downstream end, where development is occurring most rapidly. Hydraulic characteristics of the unconsolidated valley-fill aquifer were evaluated, and seepage rates in losing and gaining tributaries were calculated or estimated, in an effort to delineate the aquifer geometry and identify the factors that contribute to flooding. Results indicated that (1) Meads Creek gained about 61 cubic feet of flow per second (about 6.0 cubic feet per second per mile of stream channel) from ground-water discharge and inflow from tributaries in its 10.2-mile reach between the northernmost and southernmost measurement sites; (2) major tributaries in the northern part of the valley are not significant sources of recharge to the aquifer; and (3) major tributaries in the central and southern part of the valley provide recharge to the aquifer. The ground-water portion of streamflow in Meads Creek (excluding tributary inflow) was 11.3 cubic feet per second (ft3/s) in the central part of the valley and 17.2 ft3/s in the southern part - a total of 28.5 ft3/s. Ground-water levels were measured in 29 wells finished in unconfined deposits for construction of a potentiometric-surface map to depict directions of ground-water flow within the valley. In general, ground water flows from the edges of the valley toward Meads Creek and ultimately discharges to it. The horizontal hydraulic gradient for the entire 12-mile-long aquifer averages about 30 feet per mile, whereas the gradient in the southern fourth of the valley averages about half that - about 17 feet per mile. A water budget for the aquifer indicated that 28 percent of recharge was derived from precipitation that falls on the aquifer, 32

  9. Southern Africa

    Atmospheric Science Data Center

    2013-04-16

    article title:  Southern Africa     View larger JPEG image ... visibility of smoke plumes and haze. The southern tip of South Africa is at the bottom of the image, and Zambia is at the top. ... MISR Team. Aug 25, 2000 - South Africa to Zambia including the Okavango Delta. project:  ...

  10. Fretted Terrain Valleys

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows shallow tributary valleys in the Ismenius Lacus fretted terrain region of northern Arabia Terra. These valleys exhibit a variety of typical fretted terrain valley wall and floor textures, including a lineated, pitted material somewhat reminiscent of the surface of a brain. Origins for these features are still being debated within the Mars science community; there are no clear analogs to these landforms on Earth. This image is located near 39.9oN, 332.1oW. The picture covers an area about 3 km (1.9 mi) wide. Sunlight illuminates the scene from the lower left.

  11. Treatment for Valley Fever (Coccidioidomycosis)

    MedlinePlus

    ... National Institutes of Health (NIH) is sponsoring a randomized controlled trial to learn more about the best ... recently called attention to Valley fever and this randomized controlled trial . How is Valley fever treated? For ...

  12. Rippled Valley Floor

    NASA Technical Reports Server (NTRS)

    2005-01-01

    15 September 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a ripple-covered valley floor in the Hyblaeus Fossae region. Winds blowing up and down the length of the valley have helped to concentrate windblown grains to form these large, megaripples.

    Location near: 26.3oN, 225.1oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  13. Session: Long Valley Exploratory Well

    SciTech Connect

    Tennyson, George P. Jr.; Finger, John T.; Eichelberger, John C.; Hickox, Charles E.

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of four presentations: ''Long Valley Exploratory Well - Summary'' by George P. Tennyson, Jr.; ''The Long Valley Well - Phase II Operations'' by John T. Finger; ''Geologic results from the Long Valley Exploratory Well'' by John C. Eichelberger; and ''A Model for Large-Scale Thermal Convection in the Long Valley Geothermal Region'' by Charles E. Hickox.

  14. Groundwater Availability of the Central Valley Aquifer, California

    USGS Publications Warehouse

    Faunt, Claudia C.

    2009-01-01

    California's Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation's irrigated land is in the Central Valley, and about one-fifth of the Nation's groundwater demand is supplied from its aquifers. The Central Valley also is rapidly becoming an important area for California's expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley's population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change. This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The

  15. Smart Valley Infrastructure.

    ERIC Educational Resources Information Center

    Maule, R. William

    1994-01-01

    Discusses prototype information infrastructure projects in northern California's Silicon Valley. The strategies of the public and private telecommunications carriers vying for backbone services and industries developing end-user infrastructure technologies via office networks, set-top box networks, Internet multimedia, and "smart homes" are…

  16. Echoes of Spring Valley.

    ERIC Educational Resources Information Center

    Boyken, J. Clarine J.

    Designed to preserve the rich heritage of the rural school system which passed from the education scene in the 1930's and 1940's, this narrative, part history and part nostalgia, describes the author's own elementary education and the secure community life centered in the one room Spring Valley School in Hamilton County, Iowa, in the early decades…

  17. Paradise Valley Community College

    ERIC Educational Resources Information Center

    Dale, Paul A.

    2009-01-01

    Paradise Valley Community College (PVCC), located in Phoenix, Arizona, is part of the Maricopa County Community College District (MCCCD). PVCC was founded in 1987 and in the fall of 2007 served 8,739 students in credit courses. Since 1997, PVCC has been on a quest to become a "more learning centered" college. As a result of placing student…

  18. Rift Valley Fever Review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rift Valley fever (RVF) is a disease of animals and humans that occurs in Africa and the Arabian Peninsula. A Phlebovirus in the family Bunyaviridae causes the disease that is transmitted by mosquitoes. Epidemics occur during years of unusually heavy rainfall that assessment models are being develo...

  19. Diurnal Evolution of Three-Dimensional Wind and Temperature Structure in California's Central Valley

    SciTech Connect

    Zhong, Shiyuan; Whiteman, Charles D.; Bian, Xindi

    2004-11-01

    The diurnal evolution of the three-dimensional summer season mean wind and temperature structure in California’s Sacramento and San Joaquin Valleys (collectively called the Central Valley) are investigated using data from 22 radar wind profiler/Radio Acoustic Sounding Systems (RASS) operated as part of the Central California Ozone Study in 2000. The profiler network revealed, for the first time, that the persistent summer season flow pattern documented by surface observations extends 800-1000 m above the surface. At most locations, up-valley winds persist both day and night except at the upper ends of the valleys and close to the valley sidewalls where diurnal wind reversals occur. Wind speeds exhibit pronounced diurnal oscillations, with amplitudes decreasing with height. A low-level wind maximum occurs in the lowest 300 m, with a sharp decrease in speed above the maximum. Especially well-defined nocturnal low-level jets occur at sites in the southern San Joaquin Valley, where maximum speeds of 10 m s-1 or more occur 1-2 h before midnight at heights near 300 m. The afternoon mixed layer, generally deeper than 1000 m, increases in depth with up-valley distance in both valleys. At night, temperature inversions develop in the lowest several hundred meters with near-isothermal layers above. Mean temperatures in the lowest 500 m of the valleys are always warmer than at the same altitude over the coast, and temperature increases from the lower to upper valleys. The diurnal oscillation of the coast-valley and along-valley temperature and pressure difference reach a maximum in late afternoon and a minimum in early morning. These oscillations are in phase with the diurnal variation of westerly onshore flows. The along-valley wind maxima, however, occur 1-2 h before midnight while the pressure gradient maxima are usually found just before sunset.

  20. Bringing Silicon Valley inside.

    PubMed

    Hamel, G

    1999-01-01

    In 1998, Silicon Valley companies produced 41 IPOs, which by January 1999 had a combined market capitalization of $27 billion--that works out to $54,000 in new wealth creation per worker in a single year. Multiply the number of employees in your company by $54,000. Did your business create that much new wealth last year? Half that amount? It's not a group of geniuses generating such riches. It's a business model. In Silicon Valley, ideas, capital, and talent circulate freely, gathering into whatever combinations are most likely to generate innovation and wealth. Unlike most traditional companies, which spend their energy in resource allocation--a system designed to avoid failure--the Valley operates through resource attraction--a system that nurtures innovation. In a traditional company, people with innovative ideas must go hat in hand to the guardians of the old ideas for funding and for staff. But in Silicon Valley, a slew of venture capitalists vie to attract the best new ideas, infusing relatively small amounts of capital into a portfolio of ventures. And talent is free to go to the companies offering the most exhilarating work and the greatest potential rewards. It should actually be easier for large, traditional companies to set up similar markets for capital, ideas, and talent internally. After all, big companies often already have extensive capital, marketing, and distribution resources, and a first crack at the talent in their own ranks. And some of them are doing it. The choice is yours--you can do your best to make sure you never put a dollar of capital at risk, or you can tap into the kind of wealth that's being created every day in Silicon Valley.

  1. Groundwater quality in the Owens Valley, California

    USGS Publications Warehouse

    Dawson, Barbara J. Milby; Belitz, Kenneth

    2012-01-01

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. Owens Valley is one of the study areas being evaluated. The Owens study area is approximately 1,030 square miles (2,668 square kilometers) and includes the Owens Valley groundwater basin (California Department of Water Resources, 2003). Owens Valley has a semiarid to arid climate, with average annual rainfall of about 6 inches (15 centimeters). The study area has internal drainage, with runoff primarily from the Sierra Nevada draining east to the Owens River, which flows south to Owens Lake dry lakebed at the southern end of the valley. Beginning in the early 1900s, the City of Los Angeles began diverting the flow of the Owens River to the Los Angeles Aqueduct, resulting in the evaporation of Owens Lake and the formation of the current Owens Lake dry lakebed. Land use in the study area is approximately 94 percent (%) natural, 5% agricultural, and 1% urban. The primary natural land cover is shrubland. The largest urban area is the city of Bishop (2010 population of 4,000). Groundwater in this basin is used for public and domestic water supply and for irrigation. The main water-bearing units are gravel, sand, silt, and clay derived from surrounding mountains. Recharge to the groundwater system is primarily runoff from the Sierra Nevada, and by direct infiltration of irrigation. The primary sources of discharge are pumping wells, evapotranspiration, and underflow to the Owens Lake dry lakebed. The primary aquifers in Owens Valley are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database

  2. Ground Watering of the Death Valley Region, Nevada and California

    SciTech Connect

    USGS

    2006-10-12

    Water is a precious commodity, especially in the arid southwest region of the US, where there is a limited supply of both surface water and ground water. Ground water has a variety of uses (such as agricultural, commercial, and domestic) in the Death Valley regional ground-water flow system (DVRFS) of southern Nevada and eastern California. The DVRFS, an area of about 100,000 square kilometers, contains very complex geology and hydrology. Using a computer model to represent this complex system the US Geological Survey (USGS) simulated ground-water flow in the Death Valley region for use with US Department of Energy (DOE) projects in southern Nevada. The model was created to help address contaminant cleanup activities associated with the underground nuclear testing conducted from 1951 to 1992 at the Nevada Test Site and to support the licensing process for the Nation's proposed geologic repository for high-level nuclear waste at Yucca Mountain, Nevada.

  3. Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

    USGS Publications Warehouse

    Tumbusch, Mary L.; Plume, Russell W.

    2006-01-01

    The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

  4. Southern California as seen from the Apollo 7 spacecraft

    NASA Technical Reports Server (NTRS)

    1968-01-01

    This view of southern California as seen from the Apollo 7 spacecraft during its 18th revolution of the earth. Photographed from an altitude of 124 nautical miles. The coast of California can be seen from Point Mugu southward to Oceanside. Santa Catalina can be seen below the off shore clouds. Details of the Los Angeles area are obscured by pollution which extends from Banning westard for 100 miles to beyond Malibu. In the upper portion of the photograph can be seen (left to right) the San Joaquin Valley beyond Bakersfield, the Techachapi Mountains, the Sierra Nevada, Owens Valley, Death Valley and the Mojave Desert.

  5. Valley South of Cerberus

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-413, 6 July 2003

    To date, the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) narrow angle system has only imaged about 3% of the martian surface. Thus, a new discovery can come at any time, as additional places are covered every day. This MOC image shows a portion of a shallow valley south of Cerberus that was just discovered in April 2003. The valley may have been cut but torrents of mud-laden water; alternatively, an extremely fluid lava was involved. This picture was acquired in May 2003; it covers an area 3 km (1.9 mi) wide and is illuminated from the left. North is toward the top/upper right. The picture is located near 4.6oN, 204.3oW.

  6. Water-level changes (1975-1998) in the Antelope Valley ground-water basin, California

    USGS Publications Warehouse

    Carlson, Carl S.; Phillips, Steven P.

    1998-01-01

    Antelope Valley is in the western part of the Mojave Desert in southern California, about 50 mi northeast of Los Angeles. Between 1975 and 1998, water levels in the valley have changed in response to a shift in ground-water use from agricultural to urban, declining in some areas and rising in others. A study to document these changes was conducted by the U.S. Geological Survey in cooperation with the Antelope Valley Water Group. This report presents the water-level data and the changes that occurred during this study period.

  7. The Owens Valley LWA

    NASA Astrophysics Data System (ADS)

    Hallinan, Gregg

    2014-04-01

    The Owens Valley LWA is a new array of 256 dual polarization antennas at Caltech's Owens Valley Radio Observatory (OVRO). It hosts the LEDA correlator, which provides full cross-correlation capability and enables instantaneous snapshot imaging of most of the viewable sky, as well as a dedicated back-end for transient searching. Developed in collaboration between Caltech, JPL and the LEDA and LWA consortia, the array targets the 28-88 MHz band with primary focus on high redshift HI (Dark Ages), radio transients (particularly radio exoplanets), solar dynamic imaging spectroscopy and measurement of coronal magnetic fields, and production of a full-Stokes, low frequency, all-sky catalog. The array comprises a 230m diameter dense core and outriggers at 365m capable of imaging with a resolution of 1 degree. Over the next 12 months, 32 additional antennas will be installed, powered by solar panels and serviced by optical fiber, with the goal of delivering instantaneous all-sky images with ~10' resolution. The associated data rate for the latter array will be extremely large, at 1.5 GB per integration, corresponding to 45,000 baselines x 4 polarizations x 2000 channels (60 MHz). Our collaboration is also working towards a much larger next generation array for study of HI and transients, sited at or near the Owens Valley observatory. I will briefly discuss some of the related ongoing technical development and data processing challenges.

  8. Fretted Terrain Valley Floor

    NASA Technical Reports Server (NTRS)

    2004-01-01

    30 December 2003 This December 2003 Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows lineated textures on the floor of a valley in the Deuteronilus region of Mars. Deuteronilus, and neighboring Protonilus and Nilosyrtis, have been known since the Mariner 9 mission as regions of 'fretted terrain.' In this context, 'fretted' does not mean 'worried,' it means 'eroded.' The fretted terrains of Mars are regions along the boundary between cratered highlands and northern lowland plains that have been broken-down into mesas, buttes, and valleys. On the floors of some of these valleys occurs a distinctive lineated and pitted texture--like the example shown here. The cause of the textures is not known, although for decades some scientists have speculated that ice is involved. While this is possible, it is far from a demonstrated fact. This picture is located near 40.1oN, 335.1oW, and covers an area approximately 3 km (1.9 mi) wide; sunlight illuminates the scene from the lower left.

  9. Understanding the coupled surface energy flux-valley wind system using observations in an alpine valley

    NASA Astrophysics Data System (ADS)

    Daniels, M. H.; Pardyjak, E.; Brutsaert, W. H.; Mage, R.; Parlange, M. B.

    2010-12-01

    Buoyancy-driven diurnal valley winds depend on relative partitioning of incoming solar radiation into the sensible and latent heat fluxes. Evaporation and transpiration at the surface contribute to the latent heat flux, while heating of the air near the surface results from the sensible heat flux. Thus if more moisture is available at the surface, (e.g. as soil moisture or dew) then more energy will be partitioned into the latent heat flux, and less will be available for the sensible heat flux. Presented here is an analysis of observations from surface weather stations placed throughout the La Fouly catchment (~20 km^2) in southern Switzerland during the summers of 2009 and 2010. The stations were equipped with sensors to measure atmospheric and land surface variables including: incoming solar radiation, 2 m air temperature, skin temperature, wind speed and direction, relative humidity, precipitation, soil moisture, and soil temperature. Scaling analysis is used to show how the balance between sensible and latent heat fluxes influences the buoyancy-driven valley winds. A preliminary analysis indicates that increased surface soil moisture tends to decrease the strength of slope winds both during the day and at night, while decreased soil moisture has the opposite effect. While this type of relation has been previously investigated through numerical simulations of valley or slope flows, it has not (to the authors' knowledge), been previously observed in the field.

  10. Addendum to sources of powerplant cooling water in the desert area of Southern California: a reconnaissance study

    USGS Publications Warehouse

    Koehler, J.H.; Mallory, Michael J.

    1981-01-01

    A hydrologic reconnaissance study was made in five basins in southern California previously classified as suitable for providing sufficient ground water for cooling a 1,000-megawatt electric-power generating plant. The criteria used to evaluate the basins were (1) theoretical aquifer response to pumping, (2) alternative sources of water, and (3) chemical quality of water. The basins were ranked relative to each other for the three criteria and in overall suitability. On the basis of subjective analysis, the basins were ranked in the following order for overall suitability: (1) Calzona-Vidal Valley, (2) Middle Amargosa Valley, (3) Chuckwalla Valley, (4) Soda Lake Valley, and (5) Caves Canyon Valley. (USGS)

  11. The California Valley grassland

    USGS Publications Warehouse

    Keeley, J.E.; Schoenherr, Allan A.

    1990-01-01

    Grasslands are distributed throughout California from Oregon to Baja California Norte and from the coast to the desert (Brown 1982) (Figure 1). This review will focus on the dominant formation in cismontane California, a community referred to as Valley Grassland (Munz 1959). Today, Valley Grassland is dominated by non-native annual grasses in genera such as Avena (wild oat), Bromus (brome grass), and Hordeum (barley), and is often referred to as the California annual grassland. On localized sites, native perennial bunchgrasses such as Stipa pultra (purple needle grass) may dominate and such sites are interpreted to be remnants of the pristine valley grassland. In northwestern California a floristically distinct formation of the Valley Grassland, known as Coast Prairie (Munz 1959) or Northern Coastal Grassland (Holland and Keil 1989) is recognized. The dominant grasses include many native perennial bunchgrasses in genera such as Agrostis, Calamagrostis, Danthonia, Deschampsia, Festuca, Koeleria and Poa (Heady et al. 1977). Non-native annuals do not dominate, but on some sites non-native perennials like Anthoxanthum odoratum may colonize the native grassland (Foin and Hektner 1986). Elevationally, California's grasslands extend from sea level to at leas 1500 m. The upper boundary is vague because montane grassland formations are commonly referred to as meadows; a community which Munz (1959) does not recognize. Holland and Keil (1989) describe the montane meadow as an azonal community; that is, a community restricted not so much to a particular climatic zone but rather controlled by substrate characteristics. They consider poor soil-drainage an over-riding factor in the development of montane meadows and, in contrast to grasslands, meadows often remain green through the summer drought. Floristically, meadows are composed of graminoids; Cyperaceae, Juncaceae, and rhizomatous grasses such as Agropyron (wheat grass). Some bunchgrasses, such as Muhlenbergia rigens, are

  12. Synthetic River Valleys

    NASA Astrophysics Data System (ADS)

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  13. Flow Along Valley Floors

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Released 9 May 2003

    Lines indicative of flow in a valley floor (east to west) cut across similar lines in a slightly smaller valley (southeast to northwest), indicating both that material flowed along the valley floor (as opposed to across it) and that relative flow ages may be determined from crosscutting relationships.

    Image information: VIS instrument. Latitude 39.6, Longitude 31.1East (328.9). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  14. Land use in the northern Coachella Valley

    NASA Technical Reports Server (NTRS)

    Bale, J. B.; Bowden, L. W.

    1973-01-01

    Satellite imagery has proved to have great utility for monitoring land use change and as a data source for regional planning. In California, open space desert resources are under severe pressure to serve as a source for recreational gratification to individuals living in the heavily populated southern coastal plain. Concern for these sensitive arid environments has been expressed by both federal and state agencies. The northern half of the Coachella Valley has historically served as a focal point for weekend recreational activity and second homes. Since demand in this area has remained high, land use change from rural to urban residential has been occurring continuously since 1968. This area of rapid change is an ideal site to illustrate the utility of satellite imagery as a data source for planning information, and has served as the areal focus of this investigation.

  15. Researching Indigenous Indians in Southern California: Commentary, Bibliography, and Online Resources

    ERIC Educational Resources Information Center

    Sutton, Imre

    2006-01-01

    This article seeks to present a continuing bibliography of research on Southern California Indians from the past 20 years, and sometimes beyond. The coverage reaches outside the variably defined bounds of Southern California so that it includes peripheral groups such as the Timbisha Shoshone of Death Valley and one or more groups in the Owens…

  16. Global Positioning System measurements of strain accumulation across the Imperial Valley, California - 1986-1989

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; Reilinger, Robert

    1992-01-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 =/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 =/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  17. GPS measurements of strain accumulation across the Imperial Valley, California: 1986-1989

    NASA Technical Reports Server (NTRS)

    Larsen, Shawn; Reilinger, Robert

    1989-01-01

    The Global Positioning System (GPS) data collected in southern California from 1986 to 1989 indicate considerable strain accumulation across the Imperial Valley. Displacements are computed at 29 stations in and near the valley from 1986 to 1988, and at 11 sites from 1988 to 1989. The earlier measurements indicate 5.9 +/- 1.0 cm/yr right-lateral differential velocity across the valley, although the data are heavily influenced by the 1987 Superstition Hills earthquake sequence. Some measurements, especially the east-trending displacements, are suspects for large errors. The 1988 to 1989 GPS displacements are best modeled by 5.2 +/- 0.9 cm/yr of valley crossing deformation, but rates calculated from conventional geodetic measurements (3.4 to 4.3 cm/yr) fit the data nearly as well. There is evidence from GPS and Very Long Base Interferometry (VLBI) observations that the present slip rate along the southern San Andreas fault is smaller than the long-term geologic estimate, suggesting a lower earthquake potential than is currently assumed. Correspondingly, a higher earthquake potential is indicated for the San Jacinto fault. The Imperial Valley GPS sites form part of a 183 station network in southern California and northern Baja California, which spans a cross-section of the North American-Pacific plate boundary.

  18. Appalachia or the Midwest? Appalachian Cultural Awareness in Southern Ohio.

    ERIC Educational Resources Information Center

    Tribe, Deanna L.

    Twenty-eight counties of southern and eastern Ohio are part of federally-defined Appalachia. This paper considers whether or not the identity of people in this area is Appalachian, Midwestern, or just plain rural. These counties lie in the unglaciated section of the Allegheny plateau, characterized by steep valleys, narrow ridges, and coal…

  19. [The Southern Sierra Nevada continental dynamics project]. Final technical report

    SciTech Connect

    Clayton, R.W.; Saleeby, J.B.

    1997-12-16

    The main objective of this study was to determine whether or not the Southern Sierra Nevada Mountain Range is supported by a crustal root. A secondary goal was to evaluate the relationship between the Sierra Nevada Range and the adjoining Death Valley extensional province. As part of the project, two seismic profiles were executed. The first was a north-south profile running from Ridgecrest to Chafant Valley. The second was an east-west profile from Death Valley to Coalinga. An NPE shot was recorded on the east-west receiver line, and the data were analyzed by forward modeling with a staggered-grid finite-difference code. Concurrently, the authors initiated an in-depth study of lower crustal and upper mantle xenoliths hosted by Neogene volcanic rocks of the central and southern Sierra Nevada region. This initial work focused on thermobarometric estimates of representative xenolith samples aimed at understanding the vertical composition of the Sierra Nevada lithosphere.

  20. Data network, collection, and analysis in the Diamond Valley flow system, central Nevada

    USGS Publications Warehouse

    Knochenmus, Lari A.; Berger, David L.; Moreo, Michael T.; Smith, J. LaRue

    2011-01-01

    Future groundwater development and its effect on future municipal, irrigation, and alternative energy uses in the Diamond Valley flow system are of concern for officials in Eureka County, Nevada. To provide a better understanding of the groundwater resources, the U.S. Geological Survey, in cooperation with Eureka County, commenced a multi-phase study of the Diamond Valley flow system in 2005. Groundwater development primarily in southern Diamond Valley has resulted in water-level declines since the 1960s ranging from less than 5 to 100 feet. Groundwater resources in the Diamond Valley flow system outside of southern Diamond Valley have been relatively undeveloped. Data collected during phase 2 of the study (2006-09) included micrometeorological data at 4 evapotranspiration stations, 3 located in natural vegetation and 1 located in an agricultural field; groundwater levels in 95 wells; water-quality constituents in aquifers and springs at 21 locations; lithologic information from 7 recently drilled wells; and geophysical logs from 3 well sites. This report describes what was accomplished during phase 2 of the study, provides the data collected, and presents the approaches to strengthen relations between evapotranspiration rates measured at micrometeorological stations and spatially distributed groundwater discharge. This report also presents the approach to improve delineation of areas of groundwater discharge and describes the current methodology used to improve the accuracy of spatially distributed groundwater discharge rates in the Diamond Valley flow system.

  1. Salton Sea and Imperial Valley, California as seen from the Apollo 7 spacecra

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Salton Sea and Imperial Valley area of southern California, including a portion of northern Baja California, Mexico, as seen from the Apollo 7 spacecraft during its 17th revolution of the earth. Photographed from an altitude of 125 nautical miles, at ground elapsed time of 27 hours.

  2. Coachella Valley, CA

    NASA Technical Reports Server (NTRS)

    2001-01-01

    These band composites, acquired on June 4, 2000, cover a 11 by 13.5 km sub-scene in the Coachella Valley, CA. The area is shown by the yellow box on the full scene in the LOWER RIGHT corner, northwest of the Salton Sea. This is a major agricultural region of California, growing fruit and produce throughout the year. Different combinations of ASTER bands help identify the different crop types. UPPER LEFT: bands 3, 2, 1 as red, green, and blue (RGB); UPPER RIGHT: bands 4, 2, 1 as RGB; LOWER LEFT: bands 4, 3, 2 as RGB. The image is centered at 33.6 degrees north latitude, 116.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  3. Long Valley Coring Project

    USGS Publications Warehouse

    Sass, John; Finger, John; McConnel, Vicki

    1998-01-01

    In December 1997, the California Energy Commission (CEC) agreed to provide funding for Phase III continued drilling of the Long Valley Exploratory Well (LVEW) near Mammoth Lakes, CA, from its present depth. The CEC contribution of $1 million completes a funding package of $2 million from a variety of sources, which will allow the well to be cored continuously to a depth of between 11,500 and 12,500 feet. The core recovered from Phase III will be crucial to understanding the origin and history of the hydrothermal systems responsible for the filling of fractures in the basement rock. The borehole may penetrate the metamorphic roof of the large magmatic complex that has fed the volcanism responsible for the caldera and subsequent activity.

  4. Death Valley, California

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an image of Death Valley, California, centered at 36.629 degrees north latitude, 117.069 degrees west longitude. The image shows Furnace Creek alluvial fan and Furnace Creek Ranch at the far right, and the sand dunes near Stove Pipe Wells at the center. The dark fork-shaped feature between Furnace Creek fan and the dunes is a smooth flood-plain which encloses Cottonball Basin. The bright dots near the center of the image are corner refectors that have been set-up to calibrate the radar as the Shuttle passes overhead with the SIR-C/X-SAR system. The Jet Propulsion Laboratory alternative photo number is P-43883.

  5. Testing a Mars science outpost in the Antarctic dry valleys.

    PubMed

    Andersen, D T; McKay, C P; Wharton, R A; Rummel, J D

    1992-01-01

    Field research conducted in the Antarctic has been providing insights about the nature of Mars in the science disciplines of exobiology and geology. Located in the McMurdo Dry Valleys of southern Victoria Land (160 degrees and 164 degrees E longitude and 76 degrees 30' and 78 degrees 30' S latitude), research outposts are inhabited by teams of 4-6 scientists. We propose that the design of these outposts be expanded to enable meaningful tests of many of the systems that will be needed for the successful conduct of exploration activities on Mars. Although there are some important differences between the environment in the Antarctic dry valleys and on Mars, the many similarities and particularly the field science activities, make the dry valleys a useful terrestrial analog to conditions on Mars. Three areas have been identified for testing at a small science outpost in the dry valleys; 1) studying human factors and physiology in an isolated environment; 2) testing emerging technologies (e.g., innovative power management systems, advanced life support facilities including partial bioregenerative life support systems for water recycling and food growth, telerobotics, etc.); and 3) conducting basic scientific research that will enhance our understanding of Mars while contributing to the planning for human exploration. We suggest that an important early result of a Mars habitat program will be the experience gained by interfacing humans and their supporting technology in a remote and stressful environment.

  6. Testing a Mars science outpost in the Antarctic dry valleys

    NASA Astrophysics Data System (ADS)

    Andersen, D. T.; McKay, C. P.; Wharton, R. A.; Rummel, J. D.

    Field research conducted in the Antarctic has been providing insights about the nature of Mars in the science disciplines of exobiology and geology. Located in the McMurdo Dry Valleys of southern Victoria Land (160° and 164° E longitude and 76°30' and 78°30' S latitude), research outposts are inhabited by teams of 4-6 scientists. We propose that the design of these outposts be expanded to enable meaningful tests of many of the systems that will be needed for the successful conduct of exploration activities on Mars. Although there are some important differences between the environment in the Antarctic dry valleys and on Mars, the many similarities and particularly the field science activities, make the dry valleys a useful terrestrial analog to conditions on Mars. Three areas have been identified for testing at a small science outpost in the dry valleys: 1) studying human factors and physiology in an isolated environment; 2) testing emerging technologies (e.g., innovative power management systems, advanced life support facilities including partial bioregenerative life support systems for water recycling and food growth, telerobotics, etc.); and 3) conducting basic scientific research that will enhance our understanding of Mars while contributing to the planning for human exploration. We suggest that an important early result of a Mars habitat program will be the experience gained by interfacing humans and their supporting technology in a remote and stressful environment.

  7. Testing a Mars science outpost in the Antarctic dry valleys

    NASA Technical Reports Server (NTRS)

    Andersen, D. T.; Mckay, C. P.; Wharton, R. A.; Rummel, J. D.

    1992-01-01

    Field research conducted in the Antarctic has been providing insights about the nature of Mars in the science disciplines of exobiology and geology. Located in the McMurdo Dry Valleys of southern Victoria Land (160 deg and 164 deg E longitude and 76 deg 30 min and 78 deg 30 min S latitude), research outposts are inhabited by teams of 4-6 scientists. It is proposed that the design of these outposts be expanded to enable meaningful tests of many of the systems that will be needed for the successful conduct of exploration activities on Mars. Although there are some important differences between the environment in the Antarctic dry valleys and on Mars, the many similarities and particularly the field science activities, make the dry valleys a useful terrestrial analog to conditions on Mars. Three areas have been identified for testing at a small science outpost in the dry valleys: (1) studying human factors and physiology in an isolated environment; (2) testing emerging technologies (e.g. innovative power management systems, advanced life support facilities including partial bioregenerative life support systems for water recycling and food growth, telerobotics, etc.); and (3) conducting basic scientific research that will enhance understanding of Mars while contributing to the planning for human exploration. It is suggested that an important early result of a Mars habitat program will be the experience gained by interfacing humans and their supporting technology in a remote and stressful environment.

  8. 27 CFR 9.82 - Potter Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Potter Valley. 9.82... Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  9. Southern blotting.

    PubMed

    Brown, T

    2001-05-01

    Southern blotting is the transfer of DNA fragments from an electrophoresis gel to a membrane support, resulting in immobilization of the DNA fragments, so the membrane carries a semipermanent reproduction of the banding pattern of the gel. After immobilization, the DNA can be subjected to hybridization analysis, enabling bands with sequence similarity to a labeled probe to be identified. This unit describes Southern blotting via upward capillary transfer of DNA from an agarose gel onto a nylon or nitrocellulose membrane, and subsequent immobilization by UV irradiation (for nylon) or baking (for nitrocellulose). A Support Protocol describes how to calibrate a UV transilluminator for optimal UV irradiation of a nylon membrane. An alternate protocol details transfer using nylon membranes and an alkaline buffer, and is primarily used with positively charged nylon membranes. A second alternate protocol describes a transfer method based on a different transfer-stack setup. The traditional method of upward capillary transfer of DNA from gel to membrane has certain disadvantages, notably the fact that the gel can become crushed by the weighted filter papers and paper towels that are laid on top of it. This slows down the blotting process and may reduce the amount of DNA that can be transferred. The downward capillary method described in the second alternate protocol is therefore more rapid and can result in more complete transfer. PMID:18432697

  10. Revisiting the Submerged Paleo Elbe Valley (S North Sea) with High-Resolution Shallow Seismics

    NASA Astrophysics Data System (ADS)

    Papenmeier, S.; Hass, H. C.

    2014-12-01

    The Elbe paleo valley is the most prominent subsurface structure in the southern North Sea (~10,000 km²) and constitutes an important part of Germany's largest marine Natura 2000-Reserve "Sylter Außenriff" (European environmental protection area). It is supposed that the valley was formed by epeirogenic movement during the Tertiary. The depression developed to its present form during the Weichselian sea-level lowstand (-130 m below present). Melt waters that discharged in north-westerly directions fed the paleo Elbe at that time. During the Holocene the valley drowned in the rising sea. A narrow raster of new shallow seismic data combined with high resolution sidescan sonar data is used to shed new light on the Holocene development of the paleo Elbe valley and its adjacent regions in detail. Cross sections distributed with transect distances of 400 and 800 m, respectively, over a length of 100 km (approximately one third of the total valley length) enable a good comprehensive analysis of the historical process of sedimentary valley infill and coastal evolution with the successive Holocene sea level rise. The eastern flank of the valley is characterized by a relatively steep slope with one or more terraces, representing moraine deposits which are today still present at the seafloor surface, partly covered with Holocene marine deposits. The western slip-off slope of the valley is much smoother than the eastern undercut slope. West of the valley, sediment cores show peat and tidal flat sediments. Shallow seismic data show the base of the valley. There are conspicuous internal seismic reflectors above the base, inclined in northeastern direction. They indicate a sedimentary infill of the valley from the southwest when the southern part of the Dogger Bank was flooded during the early Holocene sea-level rise. In this process the steeper eastern slope acted as a natural barrier towards the northeast, averted sediment transport beyond the eastern boundary of the paleo

  11. Accelerating optimization by tracing valley

    NASA Astrophysics Data System (ADS)

    Li, Qing-Xiao; He, Rong-Qiang; Lu, Zhong-Yi

    2016-06-01

    We propose an algorithm to accelerate optimization when an objective function locally resembles a long narrow valley. In such a case, a conventional optimization algorithm usually wanders with too many tiny steps in the valley. The new algorithm approximates the valley bottom locally by a parabola that is obtained by fitting a set of successive points generated recently by a conventional optimization method. Then large steps are taken along the parabola, accompanied by fine adjustment to trace the valley bottom. The effectiveness of the new algorithm has been demonstrated by accelerating the Newton trust-region minimization method and the Levenberg-Marquardt method on the nonlinear fitting problem in exact diagonalization dynamical mean-field theory and on the classic minimization problem of the Rosenbrock's function. Many times speedup has been achieved for both problems, showing the high efficiency of the new algorithm.

  12. Principal facts for gravity stations in the vicinity of Coyote Spring Valley, Nevada, with initial gravity modeling results

    USGS Publications Warehouse

    Phelps, Geoffrey A.; Jewel, E.B.; Langenheim, V.E.; Jachens, R.C.

    2000-01-01

    Gravity measurements were made along 5 profiles across parts of the Coyote Spring Valley and vicinity in order to aid in modeling the depth and shapes of the underlying basins and to locate faults concealed beneath the basin fill. Measurements were taken at 200 m (660 ft) spacing along the profiles. Models based on these and existing regional data reveal two north-south-trending basins beneath Coyote Spring Valley that reach maximum depths of greater than 1 km (0.6 mi). A small valley, located just east of Coyote Spring Valley and containing Dead Man Wash, includes a small basin about 500 m (1600 ft) deep that appears to be the southern continuation of the northern basin beneath Coyote Spring Valley. The profile gravity data are further used to identify the locations of possible faults concealed beneath the basin fill.

  13. Southern blotting.

    PubMed

    Brown, T

    2001-05-01

    Southern blotting is the transfer of DNA fragments from an electrophoresis gel to a membrane support (the properties and advantages of the different types of membrane, transfer buffer, and transfer method are discussed in detail), resulting in immobilization of the DNA fragments, so the membrane carries a semipermanent reproduction of the banding pattern of the gel. After immobilization, the DNA can be subjected to hybridization analysis, enabling bands with sequence similarity to a labeled probe to be identified. This appendix describes Southern blotting via upward capillary transfer of DNA from an agarose gel onto a nylon or nitrocellulose membrane, using a high-salt transfer buffer to promote binding of DNA to the membrane. With the high-salt buffer, the DNA becomes bound to the membrane during transfer but not permanently immobilized. Immobilization is achieved by UV irradiation (for nylon) or baking (for nitrocellulose). A Support Protocol describes how to calibrate a UV transilluminator for optimal UV irradiation of a nylon membrane. An alternate protocol details transfer using nylon membranes and an alkaline buffer, and is primarily used with positively charged nylon membranes. The advantage of this combination is that no post-transfer immobilization step is required, as the positively charged membrane binds DNA irreversibly under alkaline transfer conditions. The method can also be used with neutral nylon membranes but less DNA will be retained. A second alternate protocol describes a transfer method based on a different transfer-stack setup. The traditional method of upward capillary transfer of DNA from gel to membrane described in the first basic and alternate protocols has certain disadvantages, notably the fact that the gel can become crushed by the weighted filter papers and paper towels that are laid on top of it. This slows down the blotting process and may reduce the amount of DNA that can be transferred. The downward capillary method described in

  14. SOUTHERN MASSANUTTEN ROADLESS AREA, VIRGINIA.

    USGS Publications Warehouse

    Lesure, Frank G.; Chatman, Mark L.

    1984-01-01

    The Southern Massanutten Roadless Area is in the George Washington National Forest in the Shenandoah Valley of Page and Rockingham Counties, Virginia. According to mineral surveys of the area, inferred resources of low-grade iron occur at two mines in folded Paleozoic sedimentary rocks. The iron resources consist of 120,000 long tons of clayey and sandy limonite. Other mineral resources occur in the area including extensive areas of high-silica sandstone, shale suitable for making brick, and limestone suitable for crushed stone and agricultural lime. The potential for the occurrence of oil or natural gas resources cannot be evaluated from the available data. The nonmetallic mineral resources are of limited importance because of relative inaccessibility as compared to large accessible resources outside the roadless area.

  15. Lower Mississippian trilobites from southern New Mexico

    USGS Publications Warehouse

    Brezinski, D.K.

    2000-01-01

    Twenty-three species of trilobites are recognized in the lower Mississippian Caballero and Lake Valley Formations of southern New Mexico. Species exhibit a segregation into shelf and off-shelf faunas, and can be subdivided into three distinct stratigraphic faunas. Species found in the Caballero Formation are similar to those found in the Chouteau Formation of Missouri. A second fauna, comprising species found in the Alamogordo, Nunn, and Tierra Blanca Members of the Lake Valley Formation, is correlated with the Fern Glen and Burlington Formations of Missouri. The third fauna found in the Arcente and Dona Aha Members of the Lake Valley Formation is correlated with the Warsaw and Salem Formations of the United States midcontinent region. Named species from the Kinderhookian Caballero Formation include: Dixiphopyge armata (Vogdes, 1891), Comptonaspis swallowi (Shumard, 1855), Brachymetopus indianwellsensis new species, Ameropiltonia perplexa new species, Griffithidella caballeroensis new species, and Kollarcephalus granatai new genus and new species. Named species from the Lake Valley Formation include: Pudoproetus fernglenensis (Weller, 1909), Breviphillipsia semiteretis Hessler, 1963, Griffithidella doris (Hall 1860), Phillibole planucauda (Brezinski, 1998), Piltonia carlakertisae new species, Australosutura llanoensis Brezinski, 1998, Thigriffides triangulatus new species, Thigriffides? alamogordoensis new species, Namuropyge newmexicoensis new species, Nunnaspis stitti new genus and new species, Hesslerides arcentensis new genus and new species, as well as an unnamed species of Proetides Hessler, 1962, Namuropyge Brezinski, 1988, and Thigriffides Hessler, 1965.

  16. SRTM Perspective View with Landsat Overlay: San Joaquin Valley, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    San Joaquin, the name given to the southern portion of California's vast Central Valley, has been called the world's richest agricultural valley. In this perspective view generated using data from the Shuttle Radar Topography Mission and an enhanced Landsat image, we are looking toward the southwest over a checkerboard pattern of agricultural fields. Mt. Pinos, a popular location for stargazing at 2,692 meters (8,831 feet) looms above the valley floor and is visible on the left side of the image. The productive southern San Joaquin is in reality a desert, averaging less than 12.7 cm (5 inches) of rain per year. Through canals and irrigation, the region nurtures some two hundred crops including grapes, figs, apricots, oranges, and more than 4,047 square-km (1,000,000 acres) of cotton. The California Aqueduct, transporting water from the Sacramento River Delta through the San Joaquin, runs along the base of the low-lying Wheeler Ridge on the left side of the image. The valley is not all agriculture though. Kern County, near the valley's southern end, is the United States' number one oil producing county, and actually produces more crude oil than Oklahoma. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors, from Landsat data, approximate natural color.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U

  17. Resistivity Imaging of Spring Valley, Nevada Using the Audiomagnetotelluric Method

    NASA Astrophysics Data System (ADS)

    McPhee, D. K.; Pellerin, L.; Chuchel, B.; Dixon, G. L.

    2005-05-01

    Audiomagnetotelluric (AMT) sounding data collected in Spring Valley, NV show significant two-dimensional (2D) structure within the upper kilometer of the valley and help define the shallow basement surface. We collected AMT data along two profiles in the southern part of Spring Valley in the Fall 2004, using the Geometrics StrataGem EH4 system, a four channel, natural and controlled-source tensor system recording in the range of 10 to 92,000 Hz. To augment the low signal in the natural field a transmitter of two horizontal-magnetic dipoles was used from 1,000 to 70,000 Hz. Profile A extends 12.6 km from the Fortification Range on the west across southern Spring Valley to the Limestone Hills in the east with soundings recorded every 200 m. Profile B is a 2-km long, roughly E-W trending line located at the northern margin of the Fortification Range, roughly parallel to and 12 km NW of Profile A, with sounding spacings of 200-400 m. Data were recorded with the electrical field (E) parallel and perpendicular to the regional geological strike direction. We computed our preferred two-dimensional, inverse models from the E perpendicular mode data using the conjugate gradient, finite-difference method of Rodi and Mackie (2001) and a 100 ohm-m half-space, starting model. Inverse models were also computed using both modes and an equivalent model resulted, with a slightly higher RMS fit, indicating the two-dimensionality of the structure. Various starting models were used to test the depth of investigation. The model along Profile A shows detailed structure within the alluvial basin. Preliminary interpretation shows a clear transition between unsaturated (200-500 ohm-m) and saturated alluvium/volcanic rocks (20-50 ohm-m) at roughly 100 m depth. Highly-resistive (>1000 ohm-m) carbonate rocks are clearly defined at the east end of Profile A, and the locations and dips of several range-front and inter-basin faults, which lack surface expression, are delineated throughout the

  18. Railroad Valley, Nevada

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Information from images of Railroad Valley, Nevada captured on August 17,2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer(ASTER) may provide a powerful tool for monitoring crop health and maintenance procedures.

    These images cover an area of north central Nevada. The top image shows irrigated fields, with healthy vegetation in red. The middle image highlights the amount of vegetation. The color code shows highest vegetation content in red, orange, yellow, green, blue, and purple and the lowest in black. The final image is a thermal infrared channel, with warmer temperatures in white and colder in black.

    In the thermal image, the northernmost and westernmost fields are markedly colder on their northwest areas, even though no differences are seen in the visible image or the second, Vegetation Index image. This can be attributed to the presence of excess water, which can lead to crop damage.

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)is an imaging instrument that is flying on Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System (EOS). The instrument is being used to obtain detailed maps of land surface temperature, emissivity, reflectance and elevation. The Earth Observing System (EOS) platforms are part of NASA's Earth Science Enterprise, whose goal is to obtain a better understanding of the interactions between the biosphere, hydrosphere, lithosphere and atmosphere.

    NASA's Jet Propulsion Laboratory is a division of the California Institute of Technology, Pasadena.

  19. [Rift Valley fever].

    PubMed

    Pépin, M

    2011-06-01

    Rift Valley Fever (RVF) is a zoonotic arbovirosis. Among animals, it mainly affects ruminants, causing abortions in gravid females and mortality among young animals. In humans, RVF virus infection is usually asymptomatic or characterized by a moderate fever. However, in 1 to 3% of cases, more severe forms of the disease (hepatitis, encephalitis, retinitis, hemorrhagic fever) can lead to the death of infected individuals or to major sequels. The RVF virus (Bunyaviridae, genus Phlebovirus) was identified for the first time in the 1930s in Kenya. It then spread over almost all African countries, sometimes causing major epizootics/epidemics. In 2000, the virus was carried out of Africa, in the Middle East Arabian Peninsula. In 2007-2008, Eastern-African countries, including Madagascar, reported significant episodes of RVF virus, this was also the case for the Comoros archipelago and the French island of Mayotte. This ability to spread associated with many vectors, including in Europe, and high viral loads in infected animals led the health authorities worldwide to warn about the potential emergence of RVF virus in areas with a temperate climate. The awareness has increased in recent years with climate changes, which may possibly modify the vector distribution and competence, and prompted many RVF virus-free countries to better prepare for a potential implantation of RVF.

  20. Upper Neogene stratigraphy and tectonics of Death Valley - A review

    USGS Publications Warehouse

    Knott, J.R.; Sarna-Wojcicki, A. M.; Machette, M.N.; Klinger, R.E.

    2005-01-01

    New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from > 3.58 Ma to < 1.1 ka. These tephra beds and tuffs establish relations among the Upper Pliocene to Middle Pleistocene sedimentary deposits at Furnace Creek basin, Nova basin, Ubehebe-Lake Rogers basin, Copper Canyon, Artists Drive, Kit Fox Hills, and Confidence Hills. New geologic formations have been described in the Confidence Hills and at Mormon Point. This new geochronology also establishes maximum and minimum ages for Quaternary alluvial fans and Lake Manly deposits. Facies associated with the tephra beds show that ???3.3 Ma the Furnace Creek basin was a northwest-southeast-trending lake flanked by alluvial fans. This paleolake extended from the Furnace Creek to Ubehebe. Based on the new stratigraphy, the Death Valley fault system can be divided into four main fault zones: the dextral, Quaternary-age Northern Death Valley fault zone; the dextral, pre-Quaternary Furnace Creek fault zone; the oblique-normal Black Mountains fault zone; and the dextral Southern Death Valley fault zone. Post -3.3 Ma geometric, structural, and kinematic changes in the Black Mountains and Towne Pass fault zones led to the break up of Furnace Creek basin and uplift of the Copper Canyon and Nova basins. Internal kinematics of northern Death Valley are interpreted as either rotation of blocks or normal slip along the northeast-southwest-trending Towne Pass and Tin Mountain fault zones within the Eastern California shear zone. ?? 2005 Elsevier B.V. All rights reserved.

  1. Hydrology of modern and late Holocene lakes, Death Valley, California

    SciTech Connect

    Grasso, D.N.

    1996-07-01

    Above-normal precipitation and surface-water runoff, which have been generally related to the cyclic recurrence of the El Nino-Southern Oscillation, have produced modern ephemeral lakes in the closed-basin Death Valley watershed. This study evaluates the regional hydroclimatic relations between precipitation, runoff, and lake transgressions in the Death Valley watershed. Recorded precipitation, runoff, and spring discharge data for the region are used in conjunction with a closed-basin, lake-water-budget equation to assess the relative contributions of water from these sources to modern lakes in Death Valley and to identify the requisite hydroclimatic changes for a late Holocene perennial lake in the valley. As part of the Yucca Mountain Site Characterization Program, an evaluation of the Quaternary regional paleoflood hydrology of the potential nuclear-waste repository site at Yucca Mountain, Nevada, was planned. The objectives of the evaluation were (1) to identify the locations and investigate the hydraulic characteristics of paleofloods and compare these with the locations and characteristics of modern floods, and (2) to evaluate the character and severity of past floods and debris flows to ascertain the potential future hazards to the potential repository during the pre-closure period (US Department of Energy, 1988). This study addresses the first of these objectives, and the second in part, by assessing and comparing the sizes, locations, and recurrence rates of modern, recorded (1962--83) floods and late Holocene paleofloods for the 8,533-mi{sup 2}, closed-basin, Death Valley watershed with its contributing drainage basins in the Yucca Mountain site area.

  2. Imperial Valley and Salton Sea, California

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Southern California's Salton Sea is a prominent visual for astronauts. This large lake supports the rich agricultural fields of the Imperial, Coachella and Mexicali Valleys in the California and Mexico desert. The Salton Sea formed by accident in 1905 when an irrigation canal ruptured, allowing the Colorado River to flood the Salton Basin. Today the Sea performs an important function as the sink for agricultural runoff; water levels are maintained by the runoff from the surrounding agricultural valleys. The Salton Sea salinity is high-nearly 1/4 saltier than ocean water-but it remains an important stopover point for migratory water birds, including several endangered species. The region also experiences several environmental problems. The recent increased demands for the limited Colorado River water threatens the amount of water allowed to flow into the Salton Sea. Increased salinity and decreased water levels could trigger several regional environmental crises. The agricultural flow into the Sea includes nutrients and agricultural by-products, increasing the productivity and likelihood of algae blooms. This image shows either a bloom, or suspended sediment (usually highly organic) in the water that has been stirred up by winds. Additional information: The Salton Sea A Brief Description of Its Current Conditions, and Potential Remediation Projects and Land Use Across the U.S.-Mexico Border Astronaut photograph STS111-E-5224 was taken by the STS-111 Space Shuttle crew that recently returned from the International Space Station. The image was taken June 12, 2002 using a digital camera. The image was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  3. A Protracted, Complex, Period of Valley Formation on Hecates Tholus Volcano, Mars

    NASA Astrophysics Data System (ADS)

    Mouginis-Mark, P. J.

    2005-12-01

    Analysis of THEMIS VIS, HRSC and MOC images of Hecates Tholus volcano, Mars, reveals an extended time period over which the volcano's extensive valley network must have evolved, and hence constrains the origin and longevity of the hydrogeologic conditions under which the valleys formed. These image data, along with MOLA topographic data, permit the following valley attributes to be identified: (1) Some valleys on the southern flank of the volcano pre-date the emplacement of the lava flows from Elysium Mons, while other valleys post-date this volcanism; (2) Braided valleys on the E. flank formed on the shallower slopes, while deeper valleys formed on steeper slopes; (3) Valleys that flooded impact craters by breaching their rims did not create any deltaic deposits within the craters, indicating low sediment loads for the water; (4) Valleys are most well developed on the NW flank of the volcano; (5) Water discharge took place within the floor of at least one impact crater, while the rim of this crater was not eroded, indicating a ground water source; (6) Valleys originated within a few kilometers of the caldera rim; and (7) No valleys formed within the summit caldera. No source for the water that carved the valleys has yet been identified, but snow melt [Fassett and Head, 2004; Lunar Planet. Sci. XXXV, no. 1113] or the remobilization of volatiles released from the degassing volcano [Scott and Wilson, 1999; JGR 104, 27,079 - 27,089] appear to be the most likely. In either model, a hydrothermal system such as the one proposed by Gulick [1998; JGR 103, 19,365 - 19,389] could have remobilized the volatiles and carved the valleys. Explosive volcanism is, therefore, still a possible style of activity for Hecates Tholus (Mouginis-Mark et al., 1982; JGR 87, 9890 - 9904), but alternative explanations for the non-uniform distribution of sub-kilometer diameter impact craters on the volcano, including glacial erosion or the rotting of surface lava flows by an active hydrothermal

  4. Tennessee Valley and Eastern Kentucky Wind Working Group

    SciTech Connect

    Katie Stokes

    2012-05-03

    In December 2009, the Southern Alliance for Clean Energy (SACE), through a partnership with the Appalachian Regional Commission, EKPC, Kentucky's Department for Energy Development and Independence, SACE, Tennessee's Department of Environment and Conservation, and TVA, and through a contract with the Department of Energy, established the Tennessee Valley and Eastern Kentucky Wind Working Group (TVEKWWG). TVEKWWG consists of a strong network of people and organizations. Working together, they provide information to various organizations and stakeholders regarding the responsible development of wind power in the state. Members include representatives from utility interests, state and federal agencies, economic development organizations, non-government organizations, local decision makers, educational institutions, and wind industry representatives. The working group is facilitated by the Southern Alliance for Clean Energy. TVEKWWG supports the Department of Energy by helping educate and inform key stakeholders about wind energy in the state of Tennessee.

  5. Valley blockade quantum switching in Silicon nanostructures.

    PubMed

    Prati, Enrico

    2011-10-01

    In analogy to the Coulomb and the Pauli spin blockade, based on the electrostatic repulsion and the Pauli exclusion principle respectively, the concept of valley blockade in Silicon nanostructures is explored. The valley parity operator is defined. Valley blockade is determined by the parity conservation of valley composition eigenvectors in quantum transport. A Silicon quantum changeover switch based on a triple of donor quantum dots capable to separate electrons having opposite valley parity by virtue of the valley parity conservation is proposed. The quantum changeover switch represents a novel kind of hybrid quantum based classical logic device.

  6. Nonlocal topological valley transport at large valley Hall angles

    NASA Astrophysics Data System (ADS)

    Beconcini, Michael; Taddei, Fabio; Polini, Marco

    2016-09-01

    Berry curvature hot spots in two-dimensional materials with broken inversion symmetry are responsible for the existence of transverse valley currents, which give rise to giant nonlocal dc voltages. Recent experiments in high-quality gapped graphene have highlighted a saturation of the nonlocal resistance as a function of the longitudinal charge resistivity ρc ,x x, when the system is driven deep into the insulating phase. The origin of this saturation is, to date, unclear. In this work we show that this behavior is fully compatible with bulk topological transport in the regime of large valley Hall angles (VHAs). We demonstrate that, for a fixed value of the valley diffusion length, the dependence of the nonlocal resistance on ρc ,x x weakens for increasing VHAs, transitioning from the standard ρc,x x 3 power law to a result that is independent of ρc ,x x.

  7. The ValleyMorph Tool: An automated extraction tool for transverse topographic symmetry (T-) factor and valley width to valley height (Vf-) ratio

    NASA Astrophysics Data System (ADS)

    Daxberger, Heidi; Dalumpines, Ron; Scott, Darren M.; Riller, Ulrich

    2014-09-01

    In tectonically active regions on Earth, shallow-crustal deformation associated with seismic hazards may pose a threat to human life and property. The study of landform development, such as analysis of the valley width to valley height ratio (Vf-ratio) and the Transverse Topographic Symmetry Factor (T-factor), delineating drainage basin symmetry, can be used as a relative measure of tectonic activity along fault-bound mountain fronts. The fast evolution of digital elevation models (DEM) provides an ideal base for remotely-sensed tectonomorphic studies of large areas using Geographical Information Systems (GIS). However, a manual extraction of the above mentioned morphologic parameters may be tedious and very time consuming. Moreover, basic GIS software suites do not provide the necessary built-in functions. Therefore, we present a newly developed, Python based, ESRI ArcGIS compatible tool and stand-alone script, the ValleyMorph Tool. This tool facilitates an automated extraction of the Vf-ratio and the T-factor data for large regions. Using a digital elevation raster and watershed polygon files as input, the tool provides output in the form of several ArcGIS data tables and shapefiles, ideal for further data manipulation and computation. This coding enables an easy application among the ArcGIS user community and code conversion to earlier ArcGIS versions. The ValleyMorph Tool is easy to use due to a simple graphical user interface. The tool is tested for the southern Central Andes using a total of 3366 watersheds.

  8. Geological and geothermal investigation of the lower Wind River valley, southwestern Washington Cascade Range

    SciTech Connect

    Berri, D.A.; Korosec, M.A.

    1983-01-01

    The detailed geology of the lower Wind River valley is presented with emphasis on those factors that bear significantly on development of a geothermal resource. The lower Wind River drainage consists primarily of the Ohanapecosh Formation, an Oligocene unit that is recognized across the entire southern Washington Cascade Range. The formation is at least 300 m thick in the Wind River valley area. It consists largely of volcaniclastic sediments, with minor massive pyroclastic flows, volcanic breccias and lava flows. Low grade zeolite facies metamorphism during the Miocene led to formation of hydrothermal minerals in Ohanapecosh strata. Metamorphism probably occurred at less than 180{sup 0}C.

  9. Southern California landslides-an overview

    USGS Publications Warehouse

    ,

    2005-01-01

    Southern California lies astride a major tectonic plate boundary defined by the San Andreas Fault and numerous related faults that are spread across a broad region. This dynamic tectonic environment has created a spectacular landscape of rugged mountains and steep-walled valleys that compose much of the region’s scenic beauty. Unfortunately, this extraordinary landscape also presents serious geologic hazards. Just as tectonic forces are steadily pushing the landscape upward, gravity is relentlessly tugging it downward. When gravity prevails, landslides can occur.

  10. Dark Valley in Newton Crater

    NASA Technical Reports Server (NTRS)

    2003-01-01

    MGS MOC Release No. MOC2-418, 11 July 2003

    This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) high resolution image shows part of a dark-floored valley system in northern Newton Crater. The valley might have been originally formed by liquid water; the dark material is probably sand that has blown into the valley in more recent times. The picture was acquired earlier this week on July 6, 2003, and is located near 39.2oS, 157.9oW. The picture covers an area 2.3 km (1.4 mi) across; sunlight illuminates the scene from the upper left.

  11. Comparison of inversion models using AIRSAR data for Death Valley, California

    NASA Technical Reports Server (NTRS)

    Kierein-Young, Kathryn S.

    1993-01-01

    Polarimetric Airborne Synthetic Aperture Radar (AIRSAR) data were collected for the Geologic Remote Sensing Field Experiment (GRSFE) over Death Valley, California, USA, in September 1989. AIRSAR is a four-look, quid-polarizaiton, three frequency instrument. It collects measurements at C-band (5.66 cm), L-band (23.98 cm), and P-band (68.13 cm), and has a GIFOV of 10 meters and a swath width of 12 kilometers. Because the radar measures at three wavelengths, different scales of surface roughness are measured. Also, dielectric constants can be calculated from the data. The scene used in this study is in Death Valley, California and is located over Trail Canyon alluvial fan, the valley floor, and Artists Drive alluvial fan. The fans are very different in mineralogic makeup, size, and surface roughness. Trail Canyon fan is located on the west side of the valley at the base of the Panamint Range and is a large fan with older areas of desert pavement and younger active channels. The source for the material on southern part of the fan is mostly quartzites and there is an area of carbonate source on the northern part of the fan. Artists Drive fan is located at the base of the Black Mountains on the east side of the valley and is a smaller, young fan with its source mostly from volcanic rocks. The valley floor contains playa and salt deposits that range from smooth to Devil's Golf course type salt pinnacles.

  12. Summer deposition of sulfate and reactive nitrogen to two alpine valleys in the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Wasiuta, Vivian; Lafrenière, Melissa J.; Norman, Ann-Lise; Hastings, Meredith G.

    2015-01-01

    Summer deposition of sulfate and reactive nitrogen (mainly nitrate, and ammonium) to two alpine valleys in the Southern Canadian Rocky Mountains was investigated to constrain their major sources and evaluate physiographic influences on deposition. The effects of elevation, aspect, and air mass trajectory were evaluated using stable isotope composition (δ15N-NO3-, δ18O-NO3-, and δ34S-SO42-) and major ion concentrations for bulk precipitation. Deposition in the two valleys was related to synoptic scale weather conditions and the route the air mass followed, the location of major emission sources relative to the study site, and atmospheric residence time. Distinct differences in deposition at a relatively small scale between two opposing alpine valleys was mainly related to the orientation of the two valleys relative to the physiography of the Western Canadian Cordillera and the dominant pathways of air mass transport. Sulfate was found to be dominantly from distant sources, while NO3- was strongly enhanced by emissions from local to regional combustion. Local to regional pollutants were preferentially transported to the NNW facing Robertson Valley during NW-upslope synoptic conditions while precipitation in the SE facing Haig Valley was from relatively clean air with minimal influence from local and regional pollutants particularly at the highest elevation site.

  13. 27 CFR 9.153 - Redwood Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Boundary. The Redwood Valley viticultural area is located in the east central interior portion of Mendocino County, California. The boundaries of the Redwood Valley viticultural area, using landmarks and points...

  14. 27 CFR 9.153 - Redwood Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Boundary. The Redwood Valley viticultural area is located in the east central interior portion of Mendocino County, California. The boundaries of the Redwood Valley viticultural area, using landmarks and points...

  15. 27 CFR 9.153 - Redwood Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Boundary. The Redwood Valley viticultural area is located in the east central interior portion of Mendocino County, California. The boundaries of the Redwood Valley viticultural area, using landmarks and points...

  16. 27 CFR 9.153 - Redwood Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Boundary. The Redwood Valley viticultural area is located in the east central interior portion of Mendocino County, California. The boundaries of the Redwood Valley viticultural area, using landmarks and points...

  17. Valley evolution by meandering rivers

    NASA Astrophysics Data System (ADS)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  18. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Green Valley of Russian... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described in this section is “Green Valley of Russian River Valley”. For purposes of part 4 of this...

  19. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Green Valley of Russian... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described in this section is “Green Valley of Russian River Valley”. For purposes of part 4 of this...

  20. Late Quaternary environments in Ruby Valley, Nevada

    USGS Publications Warehouse

    Thompson, R.S.

    1992-01-01

    Palynological data from sediment cores from the Ruby Marshes provide a record of environmental and climatic changes over the last 40,000 yr. The modern marsh waters are fresh, but no deeper than ???3 m. A shallow saline lake occupied this basin during the middle Wisconsin, followed by fresh and perhaps deep waters by 18,000 to 15,000 yr B.P. No sediments were recovered for the period between 15,000 and 11,000 yr B.P., possibly due to lake desiccation. By 10,800 yr B.P. a fresh-water lake was again present, and deeper-than-modern conditions lasted until 6800 yr B.P. The middle Holocene was characterized by very shallow water, and perhaps complete desiccation. The marsh system deepened after 4700 yr B.P., and fresh-water conditions persisted until modern times. Vegetation changes in Ruby Valley were more gradual than those seen in the paleolimno-logical record. Sagebrush steppe was more widespread than at present through the late Pleistocene and early Holocene, giving way somewhat to expanded shadscale vegetation between 8500 and 6800 yr B.P. Shadscale steppe contracted by 4000 yr B.P., but had greater than modern coverage until 1000 to 500 yr ago. Pinyon-juniper woodland was established in the southern Ruby Mountains by 4700 yr B.P. ?? 1992.

  1. Magnetotelluric Data, San Luis Valley, Colorado

    USGS Publications Warehouse

    Rodriguez, Brian D.; Williams, Jackie M.

    2008-01-01

    The San Luis Valley region population is growing. Water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region?s ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Santa Fe Group and the nature of the sedimentary deposits that fill the Rio Grande rift, which contain the principal ground-water aquifers. The shallow unconfined aquifer and the deeper confined Santa Fe Group aquifer in the San Luis Basin are the main sources of municipal water for the region. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the San Luis Basin located in southern Colorado. Detailed geologic mapping, high-resolution airborne magnetic surveys, gravity surveys, an electromagnetic survey (called magnetotellurics, or MT), and hydrologic and lithologic data are being used to better understand the aquifers. The MT survey primary goal is to map changes in electrical resistivity with depth that are related to differences in rock types. These various rock types help control the properties of aquifers. This report does not include any data interpretation. Its purpose is to release the MT data acquired at 24 stations. Two of the stations were collected near Santa Fe, New Mexico, near deep wildcat wells. Well logs from those wells will help tie future interpretations of this data with geologic units from the Santa Fe Group sediments to Precambrian basement.

  2. Soil formation in the Tsauchab Valley, Namibia

    NASA Astrophysics Data System (ADS)

    Eden, Marie; Bens, Oliver; Ramisch, Arne; Schwindt, Daniel; Völkel, Jörg

    2016-04-01

    The BMBF-funded project GeoArchives (Spaces) investigates soils and sediments in Southern Africa. A focus area lies on the Tsauchab Valley (Namibia), South of the Naukluft mountain range (24°26'40'' S, 16°10'40'' E). On a gently sloping alluvial fan facing East towards the river, the surface is characterized by a desert pavement covering soils used as farmland. The landscape units were mapped and the area at the lower slope of a hill was divided into three units: a rinsing surface and a gravel plain, separated by a channel. On these surfaces soil profiles were excavated. Profile description followed the German system (Bodenkundliche Kartieranleitung KA 5) and disturbed samples were taken at various depths and analysed in the lab. Undisturbed soil cores with a volume of 100 cm³ were taken just below the surface at a depth of ~1-6 cm. Lab analyses included texture and gravel content, colour, pH, electrical conductivity, carbonates, CNS, cation exchange capacity, pedogenic oxides, main and trace elements (XRF), and clay mineral distribution (XRD). Undisturbed samples were used to determine soil water retention curve, air permeability and bulk density. The profiles revealed moderately developed cambic soils rich in clay minerals and with total carbon contents ranging up to 1.8 %, bearing shrubs and after episodic rainfall a dense grass vegetation. Their genesis is discussed and interpreted in the context of the landscape and climate history of this semi-desert environment.

  3. 27 CFR 9.46 - Livermore Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., (1956, Photorevised 1971, Minor Revision 1994); (8) Mendenhall Springs, CA (1996); (9) La Costa Valley... Valley viticultural area is located in the State of California in Contra Costa and Alameda Counties. The.../R2E range line on the La Costa Valley map, T4S; then (16) Continue southwest in a straight...

  4. 27 CFR 9.46 - Livermore Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., (1956, Photorevised 1971, Minor Revision 1994); (8) Mendenhall Springs, CA (1996); (9) La Costa Valley... Valley viticultural area is located in the State of California in Contra Costa and Alameda Counties. The.../R2E range line on the La Costa Valley map, T4S; then (16) Continue southwest in a straight...

  5. 27 CFR 9.46 - Livermore Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., (1956, Photorevised 1971, Minor Revision 1994); (8) Mendenhall Springs, CA (1996); (9) La Costa Valley... Valley viticultural area is located in the State of California in Contra Costa and Alameda Counties. The.../R2E range line on the La Costa Valley map, T4S; then (16) Continue southwest in a straight...

  6. 27 CFR 9.46 - Livermore Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., (1956, Photorevised 1971, Minor Revision 1994); (8) Mendenhall Springs, CA (1996); (9) La Costa Valley... Valley viticultural area is located in the State of California in Contra Costa and Alameda Counties. The.../R2E range line on the La Costa Valley map, T4S; then (16) Continue southwest in a straight...

  7. 27 CFR 9.46 - Livermore Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., (1956, Photorevised 1971, Minor Revision 1994); (8) Mendenhall Springs, CA (1996); (9) La Costa Valley... Valley viticultural area is located in the State of California in Contra Costa and Alameda Counties. The.../R2E range line on the La Costa Valley map, T4S; then (16) Continue southwest in a straight...

  8. 27 CFR 9.82 - Potter Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.82 Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  9. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural area described in this section is “Sonoma Valley.” (b) Approved maps. The maps showing the boundaries of the Sonoma valley viticultural area...

  10. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural area described in this section is “Sonoma Valley.” (b) Approved maps. The maps showing the boundaries of the Sonoma valley viticultural area...

  11. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.” (b) Approved maps. The maps showing the boundaries of the Napa Valley viticultural area are the: (1) “Mt....

  12. 27 CFR 9.100 - Mesilla Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.100 Mesilla Valley. (a) Name. The name of the viticultural area described in this section is “Mesilla Valley.” (b) Approved maps. The appropriate maps for determining the boundaries of Mesilla Valley...

  13. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural area described in this section is “Sonoma Valley.” (b) Approved maps. The maps showing the boundaries of the Sonoma valley viticultural area...

  14. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.58 Carmel Valley. (a) Name. The name of the viticultural area described in this section is “Carmel Valley.” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley...

  15. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural area described in this section is “Sonoma Valley.” (b) Approved maps. The maps showing the boundaries of the Sonoma valley viticultural area...

  16. 27 CFR 9.69 - Yakima Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.69 Yakima Valley. (a) Name. The name of the viticultural area described in this section is “Yakima Valley.” (b) Approved maps. The approved maps for determining the boundary of the Yakima Valley...

  17. 27 CFR 9.69 - Yakima Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.69 Yakima Valley. (a) Name. The name of the viticultural area described in this section is “Yakima Valley.” (b) Approved maps. The approved maps for determining the boundary of the Yakima Valley...

  18. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.” (b) Approved maps. The maps showing the boundaries of the Napa Valley viticultural area are the: (1) “Mt....

  19. 27 CFR 9.69 - Yakima Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.69 Yakima Valley. (a) Name. The name of the viticultural area described in this section is “Yakima Valley.” (b) Approved maps. The approved maps for determining the boundary of the Yakima Valley...

  20. 27 CFR 9.82 - Potter Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.82 Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  1. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.58 Carmel Valley. (a) Name. The name of the viticultural area described in this section is “Carmel Valley.” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley...

  2. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.58 Carmel Valley. (a) Name. The name of the viticultural area described in this section is “Carmel Valley.” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley...

  3. 27 CFR 9.50 - Temecula Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.50 Temecula Valley. (a) Name. The name of the viticultural area described in this section is “Temecula Valley.” (b) Approved map.The approved maps for determining the boundary of the Temecula Valley...

  4. 27 CFR 9.82 - Potter Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.82 Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  5. 27 CFR 9.82 - Potter Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.82 Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  6. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.” (b) Approved maps. The maps showing the boundaries of the Napa Valley viticultural area are the: (1) “Mt....

  7. 27 CFR 9.29 - Sonoma Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.29 Sonoma Valley. (a) Name. The name of the viticultural area described in this section is “Sonoma Valley.” (b) Approved maps. The maps showing the boundaries of the Sonoma valley viticultural area...

  8. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.” (b) Approved maps. The maps showing the boundaries of the Napa Valley viticultural area are the: (1) “Mt....

  9. 27 CFR 9.23 - Napa Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.” (b) Approved maps. The maps showing the boundaries of the Napa Valley viticultural area are the: (1) “Mt....

  10. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.58 Carmel Valley. (a) Name. The name of the viticultural area described in this section is “Carmel Valley.” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley...

  11. 27 CFR 9.100 - Mesilla Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.100 Mesilla Valley. (a) Name. The name of the viticultural area described in this section is “Mesilla Valley.” (b) Approved maps. The appropriate maps for determining the boundaries of Mesilla Valley...

  12. 27 CFR 9.58 - Carmel Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.58 Carmel Valley. (a) Name. The name of the viticultural area described in this section is “Carmel Valley.” (b) Approved maps. The approved maps for determining the boundary of the Carmel Valley...

  13. 27 CFR 9.100 - Mesilla Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.100 Mesilla Valley. (a) Name. The name of the viticultural area described in this section is “Mesilla Valley.” (b) Approved maps. The appropriate maps for determining the boundaries of Mesilla Valley...

  14. Birds of the St. Croix River valley: Minnesota and Wisconsin

    USGS Publications Warehouse

    Faanes, Craig A.

    1981-01-01

    The St. Croix River Valley encompasses nearly 11,550 km2 in east-central Minnesota and northwestern Wisconsin. A wide range of habitats are available for birds including upland oak, lowland deciduous, maple-basswood, lowland and upland coniferous forests, natural basin wetlands, and grasslands. Situated in the north-central region of the United States, the valley is a biological 'crossroads' for many species. Because of the mixed affinities of plant communities, the valley includes the northern and southern range limits for a number of species. Also, because the valley lies near the forest-prairie transition zone, many typical western breeding species (e.g. pintail, western meadowlark, yellow-headed blackbird) breed in proximity to typical eastern species such as tufted titmouse, eastern meadowlark, and cardinal. From 1966 to 1980, I conducted extensive surveys of avian distribution and abundance in the St. Croix River Valley. I have supplemented the results of these surveys with published and unpublished observations contributed by many ornithologists. These additional data include compilations from Christmas Bird Counts sponsored by the National Audubon Society and from the Breeding Bird Survey coordinated by the U.S. Fish and Wildlife Service. Three hundred fourteen species have been recorded in the study area; data are presented on the migration period, nesting season distribution, winter distribution, relative abundance, and habitat use of each species. Recognizing the uniqueness of the area, and its importance not only to wildlife but also to man, the U.S. Congress designated the St. Croix a National Scenic Riverway. This action provided a considerable degree of protection to lands along and directly adjacent to the river. Unfortunately, no similar legal measure exists to protect lands away from the river. With the exception of the northern quarter of the St. Croix River Valley, agricultural interests have made significant inroads into the habitat base. The

  15. Intersection of Southern Parkway and Southern Heights, looking toward the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Intersection of Southern Parkway and Southern Heights, looking toward the Beechmont Historic District, showing changes in landscaping, northeast - Southern Heights-Beechmont District Landscapes, Louisville, Jefferson County, KY

  16. The Performance of RAMS in Representing the Convective Boundary Layer Structure in a Very Steep Valley

    SciTech Connect

    De Wekker, Stephan; Steyn, D. G.; Fast, Jerome D.; Rotach, Mathias W.; Zhong, Shiyuan

    2005-04-01

    Data from a comprehensive field study in the Riviera Valley of Southern Switzerland are used to investigate convective boundary layer structure in a steep valley and to evaluate wind and temperature fields, convective boundary layer height, and surface sensible heat fluxes as predicted by the mesoscale model RAMS. Current parameterizations of surface and boundary layer processes in RAMS, as well as in other mesoscale models, are based on scaling laws strictly valid only for flat topography and uniform land cover. Model evaluation is required to investigate whether this limits the applicability of RAMS in steep, inhomogeneous terrain. One clear-sky day with light synoptic winds is selected from the field study. Observed temperature structure across and along the valley is nearly homogeneous while wind structure is complex with a wind speed maximum on one side of the valley. Upvalley flows are not purely thermally driven and mechanical effects near the valley entrance also affect the wind structure. RAMS captured many of the observed boundary layer characteristics within the steep valley. The wind field, temperature structure, and convective boundary layer height in the valley are qualitatively simulated by RAMS, but the horizontal temperature structure across and along the valley is less homogeneous in the model than in the observations. The model reproduced the observed net radiation, except around sunset and sunrise when RAMS does not take into account the shadows cast by the surrounding topography. The observed sensible heat fluxes fall within the range of simulated values at grid points surrounding the measurement sites. Some of the scatter between observed and simulated turbulent sensible heat fluxes are due to sub-grid scale effects related to local topography.

  17. McMurdo Dry Valleys

    NASA Technical Reports Server (NTRS)

    2002-01-01

    One of the few areas of Antarctica not covered by thousands of meters of ice, the McMurdo Dry Valleys stand out in this satellite image. For a few weeks each summer temperatures are warm enough to melt glacial ice, creating streams that feed freshwater lakes that lie at the bottom of the valleys. Beneath a cap of ice these lakes remains unfrozen year-round, supporting colonies of bacteria and phytoplankton. Over the past 14 years, however, summers have been colder than usual, and the lakes are becoming more and more frozen. If the trend continues, the biological communities they support may go into hibernation. Most of Antarctica has cooled along with the Dry Valleys, in contrast to much of the rest of the Earth, which has warmed over the past 100 years. No one knows if the trend is related to global climate, or just a quirk in the weather. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) instrument on December 18, 1999. For more information, visit: National Public Radio's Mixed Signals from Antarctica Declassified Satellite Imagery of the McMurdo Dry Valleys Image by Robert Simmon, based on data provided by the NASA GSFC Oceans and Ice Branch and the Landsat 7 Science Team

  18. Atmospheric turbidity over Kathmandu valley

    NASA Astrophysics Data System (ADS)

    Sapkota, Balkrishna; Dhaubhadel, Rajan

    The atmosphere of Kathmandu Valley has been investigated by using Sunphotometer and Nephelometer during the pre-monsoon period of 1999. The atmospheric turbidity parameters (extinction coefficient for 500 nm wavelength τAG and Angstrom coefficient β) are found high in the morning and show decreasing trends from morning to late afternoon on average. Vertical dispersion of pollutants and increasing pollutant flushing rate by increasing wind speed from morning to late afternoon is the cause for this decreasing trend of turbidity over the valley. Being surrounded by high hills all around the valley, horizontal exit of pollutants without vertical dispersion is not possible. The scattering coefficient bscat of aerosols in ground level troposphere is also found high in the morning, which decreases and becomes minimum during afternoon. During late afternoon, bscat again shows a slightly increasing trend. The reason is the increasing vehicular emission during late afternoon rush period. The average values of Angstrom exponent α, β, τAG and bscat are found to be 0.624±0.023, 0.299±0.009, 0.602±0.022 and 0.353±0.014 km -1, respectively. About 76.8% of the observed values of β lie above 0.2 indicating heavy particulate pollution in the valley. A comparison of observed values of turbidity parameters with other major cities of the world shows that Kathmandu is as polluted as cities like Jakarta, Kansas, Beijing, Vienna, etc.

  19. Navigating the valley of death

    NASA Astrophysics Data System (ADS)

    Dacey, James

    2014-11-01

    Taking an innovation from the lab to the market is hard in any discipline, but physics start-ups face some unique challenges crossing the so-called "valley of death". James Dacey speaks to scientists and business professionals in the Boston area of the US who have dared to take on this journey.

  20. Climate change and agricultural transformation in the Oaxaca Valley, Mexico

    SciTech Connect

    Dilley, F.B.

    1993-01-01

    The Valley of Oaxaca, a semi-arid region in the central highlands of southern Mexico, provides a case study through which to develop a methodology for climate change impact assessment. The causes and impacts of climate change originate in dialectic processes within a nexus of inter-dependent social, technical, environmental, cultural and academic production relations. Agriculture is the most important economic activity in the Valley, and rain-fed maize the most important crop. Harvest failures from droughts occur one year in four. Annual rainfall varies with large-scale convection of water vapor transported from the Pacific and Gulf of Mexico during summer, upper-air disturbances caused by hurricanes and El Ninos. Variations in maize yields and losses have roughly moisture availability during August. Yields and losses can be predicted using precipitation during this time, or directly from atmospheric circulation. Contemporary agriculture in the Valley of Oaxaca has both traditional and modern sectors, of which both may appear within individual communities and households. The traditional sector consists of semi-autonomous rural communities using traditional technology for subsistence farming. The modern sector uses tractors, irrigation pumps, agricultural chemicals and hybrid seeds to produce cash crops and dairy products. The evidence for climate change in the Valley is ambiguous and contradictory. Under wet or dry scenarios, climate change affects the rate and pathway of the absorption of Oaxaca's traditional rural communities into the wage labor market of the larger capitalist system. Increased moisture availability would raise land productivity, promoting cash cropping and development of the modern market-oriented agricultural sector and leading to land consolidation and rural-to-urban migration. Decreased moisture availability would inhibit cash-cropping but also lead to rural-to-urban migration due to decreased land productivity.

  1. Shallow Seismic Reflection Survey at Garner Valley Digital Array

    NASA Astrophysics Data System (ADS)

    Lawrence, Z. S.; Brackman, T. B.; Bodin, P.; Stephenson, W. J.; Steidl, J. H.; Gomberg, J.

    2004-12-01

    The Garner Valley Digital Array (GVDA) site is a NEES-sponsored facility in a small, sediment-filled, intermountain valley in Southern California, established for the purpose of investigating ground motion site response and soil-structure interaction, in situ. The site has been well-characterized geotechnically, and is thoroughly instrumented with both surface and downhole instrumentation of various types. Nevertheless, a borehole recently drilled into lake bed sediments and deeply weathered granitic rocks that comprise the valley fill at GVDA encountered hard, unweathered bedrock at an unexpected depth, suggesting an apparent 38 meter offset in the unweathered bedrock between two wells 40 meters apart. The apparent offset can be most easily explained either by faulting, or as a buried erosional surface. The Hot Springs fault, a strand of the San Jacinto fault zone, runs through Garner Valley, although its inferred location is several hundred meters east of GVDA. To better characterize the subsurface strata, particularly the existence and configuration of faulting that may disturb them; we conducted a 120-meter long, 12-fold shallow seismic reflection common midpoint (CMP) survey at GVDA using a 24-channel seismograph, vertical 4.5 Hz geophones at 2-meter intervals and a sledgehammer seismic source. Preliminary processing reveals strong refractors and surface waves that may mask reflections, although reflections are visible in some raw shot records. Semi-continuous reflections seen in the CMP section from a shallow reflector may coincide with the water table. There are also deeper, discontinuous reflectors obscured by bands of coherent noise. We plan to present a fully migrated and interpreted CMP record section.

  2. Spirit's West Valley Panorama

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA'S Mars Exploration Rover Spirit captured this westward view from atop a low plateau where Sprit spent the closing months of 2007.

    After several months near the base of the plateau called 'Home Plate' in the inner basin of the Columbia Hills range inside Gusev Crater, Spirit climbed onto the eastern edge of the plateau during the rover's 1,306th Martian day, or sol, (Sept. 5, 2007). It examined rocks and soils at several locations on the southern half of Home Plate during September and October. It was perched near the western edge of Home Plate when it used its panoramic camera (Pancam) to take the images used in this view on sols 1,366 through 1,369 (Nov. 6 through Nov. 9, 2007). With its daily solar-energy supply shrinking as Martian summer turned to fall, Spirit then drove to the northern edge of Home Plate for a favorable winter haven. The rover reached that northward-tilting site in December, in time for the fourth Earth-year anniversary of its landing on Mars. Spirit reached Mars on Jan. 4, 2004, Universal Time (Jan. 3, 2004, Pacific Standard Time). It landed at a site at about the center of the horizon in this image.

    This panorama covers a scene spanning left to right from southwest to northeast. The western edge of Home Plate is in the foreground, generally lighter in tone than the more distant parts of the scene. A rock-dotted hill in the middle distance across the left third of the image is 'Tsiolkovski Ridge,' about 30 meters or 100 feet from the edge of Home Plate and about that same distance across. A bump on the horizon above the left edge of Tsiolkovski Ridge is 'Grissom Hill,' about 8 kilometers or 5 miles away. At right, the highest point of the horizon is 'Husband Hill,' to the north and about 800 meters or half a mile away.

    This view combines separate images taken through Pancam filters centered on wavelengths of 753 nanometers, 535 nanometers and 432 nanometers to produce an approximately true-color panorama.

  3. Topological spin and valley pumping in silicene

    NASA Astrophysics Data System (ADS)

    Luo, Wei; Sheng, L.; Wang, B. G.; Xing, D. Y.

    2016-08-01

    We propose to realize adiabatic topological spin and valley pumping by using silicene, subject to the modulation of an in-plane ac electric field with amplitude Ey and a vertical electric field consisting of an electrostatic component and an ac component with amplitudes and . By tuning and , topological valley pumping or spin-valley pumping can be achieved. The low-noise valley and spin currents generated can be useful in valleytronic and spintronic applications. Our work also demonstrates that bulk topological spin or valley pumping is a general characteristic effect of two-dimensional topological insulators, irrelevant to the edge state physics.

  4. Topological spin and valley pumping in silicene

    PubMed Central

    Luo, Wei; Sheng, L.; Wang, B. G.; Xing, D. Y.

    2016-01-01

    We propose to realize adiabatic topological spin and valley pumping by using silicene, subject to the modulation of an in-plane ac electric field with amplitude Ey and a vertical electric field consisting of an electrostatic component and an ac component with amplitudes and . By tuning and , topological valley pumping or spin-valley pumping can be achieved. The low-noise valley and spin currents generated can be useful in valleytronic and spintronic applications. Our work also demonstrates that bulk topological spin or valley pumping is a general characteristic effect of two-dimensional topological insulators, irrelevant to the edge state physics. PMID:27507592

  5. Sediments, geomorphology, magnetostratigraphy, and vertebrate paleontology in the San Pedro Valley, Arizona

    SciTech Connect

    Lindsay, E.H.; Smith, G.A.; Haynes, C.V.; Opdyke, N.D. )

    1990-07-01

    The San Pedro Valley in southern Arizona was probably formed by block faulting during the Miocene. Sediments that filled the valley, primarily the St. David Formation, have yielded a robust vertebrate fossil record, calibrated during the last 25 years by magnetostratigraphy and isotopic dating of volcanic ejecta. This chronologic framework is combined with new sedimentologic, paleomagnetic, and geomorphic data to evaluate the influence of subsequent tectonism within the basin. The authors conclude that tectonism in the San Pedro Valley has been relatively quiescent following the initial block faulting and suggest that ensuring rates of sedimentation and incision were most likely controlled by climatic factors rather than tectonic-geologic ones. Vertebrate datum planes established in 1975 are revised on the basis of new paleontologic and geologic-isotopic data. The authors now recognize only three faunal datum planes in the St. David Formation, and have abandoned the youngest (Lepus) datum plane.

  6. Airborne electromagnetic and magnetic survey data of the Paradox and San Luis Valleys, Colorado

    USGS Publications Warehouse

    Ball, Lyndsay B.; Bloss, Benjamin R.; Bedrosian, Paul A.; Grauch, V.J.S.; Smith, Bruce D.

    2015-01-01

    In October 2011, the U.S. Geological Survey (USGS) contracted airborne magnetic and electromagnetic surveys of the Paradox and San Luis Valleys in southern Colorado, United States. These airborne geophysical surveys provide high-resolution and spatially comprehensive datasets characterizing the resistivity structure of the shallow subsurface of each survey region, accompanied by magnetic-field information over matching areas. These data were collected to provide insight into the distribution of groundwater brine in the Paradox Valley, the extent of clay aquitards in the San Luis Valley, and to improve our understanding of the geologic framework for both regions. This report describes these contracted surveys and releases digital data supplied under contract to the USGS.

  7. Global positioning system surveying to monitor land subsidence in Sacramento Valley, California, USA

    USGS Publications Warehouse

    Ikehara, M.E.

    1994-01-01

    A subsidence research program began in 1985 to document the extent and magnitude of land subsidence in Sacramento Valley, California, an area of about 15 600 km2m, using Global Positioning System (GPS) surveying. In addition to periodic conventional spirit levelling, an examination was made of the changes in GPS-derived ellipsoidal height differences (summary differences) between pairs of adjacent bench marks in central Sacramento Valley from 1986 to 1989. The average rates of land subsidence in the southern Sacramento Valley for the past several decades were determined by comparing GPS-derived orthometric heights with historic published elevations. A maximum average rate of 0.053 m year-1 (0.90 m in 17 years) of subsidence has been measured. -Author

  8. Early Permian conodont fauna and stratigraphy of the Garden Valley Formation, Eureka County, Nevada

    USGS Publications Warehouse

    Wardlaw, Bruce R.; Gallegos, Dora M.; Chernykh, Valery V.; Snyder, Walter S.

    2015-01-01

    The lower Part of the Garden Valley Formation yields two distinct conodont faunas. One of late Asselian age dominated by Mesogondolella and Streptognathodus and one of Artinskian age dominated by Sweetognathus with Mesogondolella. The Asselian fauna contains the same species as those found in the type area of the Asselian in the southern Urals including Mesogondolella dentiseparata, described for the first time outside of the Urals. Apparatuses for Sweetognathus whitei, Diplognathodus stevensi, and Idioprioniodus sp. are described. The Garden Valley Formation represents a marine pro-delta basin and platform, and marine and shore fan delta complex deposition. The fan-delta complex was most likely deposited from late Artinskian to lateWordian. The Garden Valley Formation records tremendous swings in depositional setting from shallow-water to basin to shore.

  9. Impact of climate and parent material on chemical weathering in Loess-derived soils of the Mississippi River valley

    USGS Publications Warehouse

    Muhs, D.R.; Bettis, E. Arthur; Been, J.; McGeehin, J.P.

    2001-01-01

    Peoria Loess-derived soils on uplands east of the Mississippi River valley were studied from Louisiana to Iowa, along a south-to-north gradient of decreasing precipitation and temperature. Major element analyses of deep loess in Mississippi and Illinois show that the composition of the parent material is similar in the northern and southern parts of the valley. We hypothesized that in the warmer, wetter parts of the transect, mineral weathering should be greater than in the cooler, drier parts of the transect. Profile average values of CaO/TiO2, MgO/ TiO2, K2O/TiO2, and Na2O/TiO2, Sr/Zr, Ba/Zr, and Rb/Zr represent proxies for depletion of loess minerals such as calcite, dolomite, hornblende, mica, and plagioclase. All ratios show increases from south to north, supporting the hypothesis of greater chemical weathering in the southern part of the valley. An unexpected result is that profile average values of Al2O3/TiO2 and Fe2O3/TiO2 (proxies for the relative abundance of clay minerals) show increases from south to north. This finding, while contrary to the evidence of greater chemical weathering in the southern part of the transect, is consistent with an earlier study which showed higher clay contents in Bt horizons of loess-derived soils in the northern part of the transect. We hypothesize that soils in the northern part of the valley received fine-grained loess from sources to the west of the Mississippi River valley either late in the last glacial period, during the Holocene or both. In contrast, soils in the southern part of the valley were unaffected by such additions.

  10. Foundering lithosphere imaged beneath the southern Sierra Nevada, California, USA.

    PubMed

    Boyd, Oliver S; Jones, Craig H; Sheehan, Anne F

    2004-07-30

    Seismic tomography reveals garnet-rich crust and mantle lithosphere descending into the upper mantle beneath the southeastern Sierra Nevada. The descending lithosphere consists of two layers: an iron-rich eclogite above a magnesium-rich garnet peridotite. These results place descending eclogite above and east of high P wave speed material previously imaged beneath the southern Great Valley, suggesting a previously unsuspected coherence in the lithospheric removal process. PMID:15286370

  11. Foundering lithosphere imaged beneath the southern Sierra Nevada, California, USA.

    PubMed

    Boyd, Oliver S; Jones, Craig H; Sheehan, Anne F

    2004-07-30

    Seismic tomography reveals garnet-rich crust and mantle lithosphere descending into the upper mantle beneath the southeastern Sierra Nevada. The descending lithosphere consists of two layers: an iron-rich eclogite above a magnesium-rich garnet peridotite. These results place descending eclogite above and east of high P wave speed material previously imaged beneath the southern Great Valley, suggesting a previously unsuspected coherence in the lithospheric removal process.

  12. Ground-Water Modeling of the Death Valley Region, Nevada and California

    USGS Publications Warehouse

    Belcher, W.R.; Faunt, C.C.; Sweetkind, D.S.; Blainey, J.B.; San Juan, C. A.; Laczniak, R.J.; Hill, M.C.

    2006-01-01

    The Death Valley regional ground-water flow system (DVRFS) of southern Nevada and eastern California covers an area of about 100,000 square kilometers and contains very complex geology and hydrology. Using a computer model to represent the complex system, the U.S. Geological Survey simulated ground-water flow in the Death Valley region for use with U.S. Department of Energy projects in southern Nevada. The model was created to help address contaminant cleanup activities associated with the underground nuclear testing conducted from 1951 to 1992 at the Nevada Test Site and to support the licensing process for the proposed geologic repository for high-level nuclear waste at Yucca Mountain, Nevada.

  13. Use of sequence-bounding surfaces for correlation and mapping in nonmarine, Incised-Valley reservoirs

    SciTech Connect

    Leckie, D.A.; Vanbeselaere, N.

    1995-11-01

    One of the problems with the application of sequence stratigraphy to nonmarine sediments is the use of effective surfaces for correlations. This case study from the Mannville Group of southern Saskatchewan demonstrates how major, regional bounding surfaces can be identified and correlated to produce a suite of maps that can be used for exploration purposes. In southern Saskatchewan, Cretaceous Mannville sediments, termed the Pense, Cantuar, and Success (S2) formations, overlie Jurassic S1 and older deposits. The interval, which is up to 100 m thick, was deposited over 40 to 50 m.y. and is riddled with unconformities and weathered horizons. Detailed stratigraphic correlations using well logs are difficult, imprecise, and highly suspect unless corroborated by core control. Jurassic Success S1 sediment was deposited in a restricted shallow-marine environment. The S2 was deposited as a sheet of quartzose, braided fluvial sandstone that unconformably cuts into the S1. The overlying Cantuar Formation consists of dominantly lithic sandstone, siltstone, and shale overlying a basal quartzose unit. The base of the Cantuar Formation has a high local relief and in places has eroded long, wide valleys into the Success and older Jurassic strata. The valleys were hundreds of kilometers long and up to 74 in deep. Remnants of the Success sediment are preserved as isolated, buried cuestas on the margins of the valley walls. Cantuar sediments represent the infill of an extensive valley system that took millions of years to fill. The fill was from meandering streams with abundant paleosols, shallow lacustrine, and splay deposits. The top of the Cantuar Formation is represented by chert and quartzose sandstones deposited in a north-south-trending estuarine system with several tributaries. Several play types, which are dominantly stratigraphic, have been identified and are related to the valley incision, valley fill, and preserved erosional cuesta remnants.

  14. Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

    NASA Technical Reports Server (NTRS)

    Kochel, R. Craig; Piper, Jonathan F.

    1986-01-01

    Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

  15. Morphology of large valleys on Hawaii - Evidence for groundwater sapping and comparisons with Martian valleys

    NASA Astrophysics Data System (ADS)

    Kochel, R. Craig; Piper, Jonathan F.

    1986-11-01

    Morphometric data on the runoff and sapping valleys on the slopes of Hawaii and Molokai in Hawaii are analyzed. The analysis reveals a clear distinction between the runoff valleys and sapping valleys. The Hawaiian sapping valleys are characterized by: (1) steep valley walls and flat floors, (2) amphitheater heads, (3) low drainage density, (4) paucity of downstream tributaries, (5) low frequency of up-dip tributaries, and (6) structural and stratigraphic control on valley patterns. The characteristics of the Hawaiian sapping valleys are compared to Martian valleys and experimental systems, and good correlation between the data is detected. Flume experiments were also conducted to study the evolution of sapping valleys in response to variable structure and stratigraphy.

  16. Yellowstone and Long Valley - A Comparison of Two Restless Calderas

    NASA Astrophysics Data System (ADS)

    Hill, D. P.; Smith, R. B.

    2007-12-01

    Three large, silicic calderas in the conterminous United States have explosively erupted volumes > 300 km3 within in the last 2 million years -- Yellowstone caldera (Wyoming) Long Valley caldera (California) and the Vallez caldera (New Mexico) all located in extensional tectonic environments. All have shown varying levels of historic unrest. Pronounced unrest episodes at Yellowstone and Long Valley calderas over the past three decades stimulated extensive research on these two closely monitored calderas, and we explore some emerging similarities and differences. Yellowstone caldera is underlain by a long-lived (> 17 my) upper-mantle hot-spot that has fed a series of caldera-forming, extending to the southwest across southern Idaho to central Oregon including three caldera-forming eruptions from the Yellowstone caldera system in the last 2 my, the most recent at 600,000 ybp. It is marked by relatively low density and low seismic velocities extending to depths of at least 400 km and a regional topographic swell with elevations exceeding 2000 m. The extensive Yellowstone hydrothermal system has a thermal output of 5 GW. The most recent magmatic eruption dated at 70,000 ybp. By comparison, Long Valley caldera is underlain by a relatively modest "hot-spot", the locus of which appears to be influenced by a dilatational jog between the dextral Eastern California Shear Zone and the Walker Lane and westward delamination of the dense lithospheric root of the adjacent Sierra Nevada. The Long Valley system has fed multiple eruptions of over the past 4 my and a single caldera-forming eruption at 760,000 ybp. It is marked by a limited topographic swell but with the elevation of the caldera floor and adjacent basins comparable to the 2000-plus m elevation of the Yellowstone swell. Long Valley caldera hydrothermal system has a thermal output of 0.3 GW (including a 40 MW geothermal power plant). The most recent eruptions from the Long Valley Caldera- Mono Domes volcanic field

  17. Irrigation channels of the Upper Rhone valley (Switzerland). Geomorphological analysis of a cultural heritage

    NASA Astrophysics Data System (ADS)

    Reynard, Emmanuel

    2016-04-01

    The Upper Rhone valley (Canton of Valais, Switzerland) is characterised by dry climatic conditions that explain the presence of an important network (about 800 km) of irrigation channels - called Bisses in the French-speaking part of the canton or Suonen in the German-speaking area - dating back to the Middle Ages. This network constitutes a cultural heritage and during the last 30 years these agricultural infrastructures have sparked a renewed interest for tourist and cultural reasons. Indeed, the paths along the channels are used as tourist trails and several abandoned channels have been renovated for tourist use. Based on an inventory of the Bisses/Suonen of Valais, the proposed communication has three aims: (1) to analyse the geomorphological context (morphometric analysis, structural geomorphology, main processes) of various types of channels and to show the impact of the geomorphological context on the building techniques; (2) to identify particularly active processes along the channels; (3) to classify the Bisses/Suonen according to their geomorphological value and to their geomorphological sensitivity, and to propose managing measures. Structural and climatic conditions influence the geomorphological context of the channels. In a structural point of view, irrigation channels are developed in three main contexts: (1) in the Aar Massif crystalline basement; (2) in the limestone and marl cover nappes of the Helvetic Alps; (3) in the metamorphic cover nappes of the Penninic domain. The Rhone River valley is boarded by two high mountain ranges: the Penninic Alps in the South and the Bernese Alps in the North. Because of rain shadow effects, the climate is relatively dry and, between Brig and Martigny, annual rainfall is not more than 600 mm at 500 m ASL and 800 mm at 1600 m ASL. Nevertheless, due to important vertical precipitation gradients annual rainfall totals are high at high altitudes. On the southern facing tributary valleys, the dry climatic conditions

  18. Late Cenozoic sedimentation in Pilot Knob Valley, California

    NASA Astrophysics Data System (ADS)

    Rittase, W. M.; Walker, J. D.; Kirby, E.; Andrew, J.; Wan, E.

    2012-12-01

    In Pilot Knob Valley (PKV), active inversion of a Pliocene-mid Pleistocene basin presents the opportunity to understand the spatial and temporal development of an enigmatic basin astride a major transform boundary in California. Here, a ~1000-m-thick package of exposed Late Cenozoic strata has been uplifted and tilted to the northeast. Based on new age and provenance data, we adopt the name Pilot Knob formation (PKfm) to describe much of these exposed rocks north of the Garlock fault (GF) and east of Christmas Canyon gate. Post-Miocene development of PKV is strongly influenced by the sinistral GF, the newly identified Marine Gate fault (MGF) and dextral Eastern California shear zone. The PKfm consists of three lithofacies members, from base to top: (1) rocks derived from Eagle Crags to the south; (2) Randsburg Wash lacustrine rocks; and (3) an upper member derived from the Slate Range. Tephrochronologic data from four PKfm ash samples brackets deposition of lacustrine Randsburg Wash Member rocks between 3.7-3.1 Ma and lacustrine rocks of the Slate Range Member between 1.2-0.6 Ma. A fifth tephrochronologic sample from lacustrine-distal alluvial sediments south of the GF near Christmas Canyon brackets deposition of a possible PKfm facies at ~3.1 Ma. A 3-stage tectonic model for northern PKV explains changing provenance patterns. Prior to ~3.1 Ma, the western PKV paleo-low lay north of the current GF adjacent to the southern Slate Range and connected to Searles Valley. The MGF cuts adjacent to the southern face of the Slate Range and southern Searles Valley with up to 7.5 km of sinistral oblique-normal slip between ~5-2.5 Ma. Eagle Crags fanglomerate deposition may continue after 3.7 Ma west of the Randsburg Wash-Searles Valley spillway, but these rocks have been eroded away. By ~3.7 Ma, northward progradation of Eagle Crags fanglomerate waned and lacustrine sediments were deposited north of the GF and east of the Randsburg Wash-Searles Valley spillway. At ~3.1 Ma

  19. Topographic stress perturbations in southern Davis Mountains, west Texas 1. Polarity reversal of principal stresses

    USGS Publications Warehouse

    Savage, W.Z.; Morin, R.H.

    2002-01-01

    We have applied a previously developed analytical stress model to interpret subsurface stress conditions inferred from acoustic televiewer logs obtained in two municipal water wells located in a valley in the southern Davis Mountains near Alpine, Texas. The appearance of stress-induced breakouts with orientations that shift by 90?? at two different depths in one of the wells is explained by results from exact solutions for the effects of valleys on gravity and tectonically induced subsurface stresses. The theoretical results demonstrate that above a reference depth termed the hinge point, a location that is dependent on Poisson's ratio, valley shape, and magnitude of the maximum horizontal tectonic stress normal to the long axis of the valley, horizontal stresses parallel to the valley axis are greater than those normal to it. At depths below this hinge point the situation reverses and horizontal stresses normal to the valley axis are greater than those parallel to it. Application of the theoretical model at Alpine is accommodated by the fact that nearby earthquake focal mechanisms establish an extensional stress regime with the regional maximum horizontal principal stress aligned perpendicular to the valley axis. We conclude that the localized stress field associated with a valley setting can be highly variable and that breakouts need to be examined in this context when estimating the orientations and magnitudes of regional principal stresses.

  20. The Cenozoic evolution of the San Joaquin Valley, California

    USGS Publications Warehouse

    Bartow, J. Alan

    1991-01-01

    The San Joaquin Valley, which is the southern part of the 700-km-long Great Valley of California, is an asymmetric structural trough that is filled with a prism of upper Mesozoic and Cenozoic sediments up to 9 km thick; these sediments rest on crystalline basement rocks of the southwestward-tilted Sierran block. The San Joaquin sedimentary basin is separated from the Sacramento basin to the north by the buried Stockton arch and associated Stockton fault. The buried Bakersfield arch near the south end of the valley separates the small Maricopa-Tejon subbasin at the south end of the San Joaquin basin from the remainder of the basin. Cenozoic strata in the San Joaquin basin thicken southeastward from about 800 m in the north to over 9,000 m in the south. The San Joaquin Valley can be subdivided into five regions on the basis of differing structural style. They are the northern Sierran block, the southern Sierran block, the northern Diablo homocline, the westside fold belt, and the combined Maricopa-Tejon subbasin and southmargin deformed belt. Considerable facies variation existed within the sedimentary basin, particularly in the Neogene when a thick section of marine sediment accumulated in the southern part of the basin, while a relatively thin and entirely nonmarine section was deposited in the northern part. The northern Sierran block, the stable east limb of the valley syncline between the Stockton fault and the San Joaquin River, is the least deformed region of the valley. Deformation consists mostly of a southwest tilt and only minor late Cenozoic normal faulting. The southern Sierran block, the stable east limb of the valley syncline between the San Joaquin River and the Bakersfield arch, is similar in style to the northern part of the block, but it has a higher degree of deformation. Miocene or older normal faults trend mostly north to northwest and have a net down-to-the-west displacement with individual offsets of as much as 600 m. The northern Diablo

  1. Poor, Rural, and Southern.

    ERIC Educational Resources Information Center

    Anderson, Robert E., Jr.

    Despite political gains and the lowering of social barriers, most Southern blacks still face formidable economic obstacles. More than half of rural Southern black families are living at or below poverty level. Efforts to improve their lot have included a number of cooperative and self-help community programs. The Southern Cooperative Development…

  2. A neotectonic tour of the Death Valley fault zone, Inyo County

    SciTech Connect

    Wills, C.J.

    1989-09-01

    The Death Valley fault zone has recently been evaluated by the Division of Mines and Geology for zoning under the Alquist-Priolo Special Studies Zones Act of 1972. This act requires the State Geologist to zone for special studies those faults that are sufficiently active and well defined as to constitute a potential hazard to structures from surface faulting or fault creep. The Death Valley fault zone is part of a system of faults that extends over 180 miles (300 km) from Fish Lake Valley in Nevada to the Garlock fault. The northern part of this system, the Northern Death Valley-Furnace Creek fault zone, is an active right-lateral fault zone. The southern part of the system, the Death Valley fault zone, is a right-lateral oblique-slip fault between Furnace Creek and Shoreline Butte. From Shoreline Butte to the Garlock fault, it is a right-lateral strike-slip fault. Landforms along this fault indicate that it is the source of many earthquakes and that it has been active in Holocene time. The heights of the scarps and magnitude of the smallest right-lateral offsets (4 feet; 1.2 m) suggest that the most recent of these events was M 6.5 or larger. The freshness of the geomorphic features and the youth of the offset materials suggest that event occurred late in the Holocene, and that multiple Holocene earthquakes have occurred.

  3. Chlorine-36 tracing of salinity sources in the dry valleys of Victoria land, Antarctica

    SciTech Connect

    Carlson, C.A.; Phillips, F.M. ); Elmore, D. ); Bentley, H.W. )

    1990-02-01

    Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic {sup 36}Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. {sup 36}Cl/Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl{sup {minus}} < 100 mg/l) were found to have {sup 36}Cl/Cl ratios in the range 100 {times} 10{sup {minus}15} to 1,700 {times} 10{sup {minus}15}, whereas saline waters (Cl{sup {minus}} > 1000 mg/l) had ratios in the range 9 {times} 10{sup {minus}15} to 40 {times} 10{sup {minus}15}. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal sources of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant sources of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.

  4. Chlorine-36 tracing of salinity sources in the Dry Valleys of Victoria Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Carlson, Catherine A.; Phillips, Fred M.; Elmore, David; Bentley, Harold W.

    1990-02-01

    Chlorine-36 was used to trace the origins of salts in six saline lakes in the Dry Valleys of Southern Victoria Land, Antarctica. Characteristic 36Cl signatures were estimated for the various potential chloride sources, which include atmospheric deposition, rock weathering, seawater, and deep ground water. 36Cl /Cl ratios were measured in natural waters and salts from the Dry Valleys. Dilute lake waters (Cl - < 100 mg/l) were found to have 36Cl /Cl ratios in the range 100 × 10 -15 to 1,700 × 10 -15, whereas saline waters (Cl - > 1000 mg/l) had ratios in the range 9 × 10 -15 to 40 × 10 -15. Simple mixing models were employed to quantify the relative contributions of the various chloride sources to Lake Vanda and Don Juan Pond. These results show that Lake Vanda has received its chloride from both deep ground water and the Onyx River. Don Juan Pond has received nearly all its chloride from deep ground water, probably ultimately from rock-water interaction. Deep ground water is the principal source of chloride to the lakes of Wright Valley. However, preliminary data suggest that marine-derived salts or relict sea water may be a significant source of chloride to the lakes of Taylor Valley, implying a possible recent marine invasion that did not affect Wright Valley.

  5. Surface Sediment Geochemistry in and around the Hudson Shelf Valley Offshore of New York

    NASA Astrophysics Data System (ADS)

    Mecray, E. L.; ten Brink, M. B.; Butman, B.; Denny, J.; Murray, R. W.

    2001-05-01

    The Hudson Shelf Valley, an ancient submerged portion of the Hudson River, extends across the continental shelf offshore of New York and New Jersey. Between 1959 and 1987, the area near the head of the valley was used for disposal of approximately 1.20 x 108 m3 of dredged material and sewage sludge. The distribution of metal concentrations and sediment characteristics were used to investigate the transport and fate of the sediments and their associated contaminants. Surface (0-2cm) sediments collected at 440 stations throughout the New York Bight between 1993 and 1998 were used to establish the regional distribution of pollutant metals, grain size, organic carbon, and Clostridium perfringens spores. Sediments in the New York Bight are generally sandy, however fine-grained sediments are found in the axis of the Valley. Statistical methods identified common sources and chemical mobility within groups of anthropogenic and naturally-occurring elements. High metal concentrations, fine-grained sediments, and higher organic carbon concentrations co-occur in depo-centers within the Valley. Normalization of the metal concentrations to these factors shows higher metal concentrations on the fine-grained particles in sandy areas of the Bight, particularly along the southern shore of Long Island. These distributions have implications for evaluating the impact of the mass distribution for contaminated metals in different habitats and areas. Decreasing concentrations of pollutants with time are observed, reflecting reduced contaminant loading in the upper region of the Valley; however, concentrations are still above natural background levels.

  6. Intensive early season adulticide applications decrease arbovirus transmission throughout the Coachella Valley, Riverside County, California.

    PubMed

    Lothrop, Hugh D; Lothrop, Branka B; Gomsi, Donald E; Reisen, William K

    2008-08-01

    In the Coachella Valley of California the seasonal onset of St. Louis encephalitis virus (SLEV), western equine encephalomyelitis virus (WEEV), and West Nile virus (WNV) has been detected consistently at the shoreline of the Salton Sea near the community of North Shore. The timing and intensity of initial amplification in the Culex tarsalis Coquillett/wild bird cycle at this focus seemed closely linked to the subsequent dispersal of virus to the rest of the Coachella Valley and perhaps southern California. In 2004, an attempt was made to interrupt the amplification and dispersal of WNV using ground ultra-low volume (ULV) applications of Pyrenone 25-5. Although these localized treatments were started 1 month after the initial detection in April, surveillance indicated no dispersal from this focus at this time. However, these treatments appeared to have little effect, and WNV eventually was detected throughout the valley, with seven human cases reported in the urbanized upper valley near Palm Springs. In 2005, the initial detection of WNV at North Shore at the end of May was followed rapidly by dispersal throughout the valley precluding efforts at containment. Evaluation of ground and aerial applications at North Shore during May and June 2005, respectively, indicated variable kill of sentinel mosquitoes (overall mortality: ground, 43%; air, 34%) and limited control of the target Cx. tarsalis population. In 2006, aerial ULV applications with the same chemical were begun immediately following the first detection of virus in mid-April, resulting in an apparent reduction of Cx. tarsalis abundance and delay of WNV activity in the rural lower valley and a marked decline in transmission by Culex quinquefasciatus Say populations in the densely populated upper northwestern valley with no human cases reported. PMID:18494603

  7. Neotectonics, drainage pattern and geomorphology of the orogen-parallel Upper Enns Valley (Eastern Alps)

    NASA Astrophysics Data System (ADS)

    Keil, Melanie; Neubauer, Franz

    2011-06-01

    The geomorphology and neotectonics of the Upper Enns Valley (Austria) in the Eastern Alps reveal the formation of a fault-controlled orogen-parallel valley. In the study area, the Eastern Alps have been under surface uplift since Early Miocene times. Quaternary processes such as uplift and cyclic glaciations likely interfere with neotectonic activity as the Upper Enns Valley follows the Salzach-Enns-Mariazell-Puchberg (SEMP) fault. The geomorphologically different landscapes comprise three main tectonic units: (1) the Austroalpine crystalline basement exposed in the Niedere Tauern, (2) the Austroalpine Paleozoic units (Greywacke Zone) and (3) the Dachstein Plateau dominated by Triassic carbonate successions. The Upper Pleistocene Ramsau Conglomerate overlying the Greywacke Zone on the northern slope of the Upper Enns Valley is a crucial element to reconstruct the evolution of the valley. A new 14C date (uncalibrated) indicates an age older than 53,300 years, outside of the analytical limit of the methods. Provenance analysis of the Ramsau Conglomerate shows the Niedere Tauern as a source region and consequently a post-early Late Pleistocene dissection of the landscape by the Upper Enns Valley. Paleosurfaces at elevations of about 1100 m on the northern and southern slopes of the Upper Enns Valley allow us to estimate surface uplift/incision of about 2.5 mm/yr. Regularly oriented outcrop-scale faults and joints of the Ramsau Conglomerate document Pleistocene to Holocene tectonic deformation, which is consistent with ongoing seismicity. Paleostress tensors deduced from slickensides and striae of pre-Cenozoic basement rocks indicate two stages of Late Cretaceous to Paleogene deformation independent of the SEMP fault; the Oligocene-Neogene evolution comprises NW-SE strike-slip compression followed by E-W compression and Late Pleistocene ca. E-W extension, the latter recorded in the Ramsau Conglomerate.

  8. Observations and numerical simulations of downslope flow separation at a valley inversion

    NASA Astrophysics Data System (ADS)

    Strauss, Lukas; Serafin, Stefano; Grubišić, Vanda

    2016-04-01

    Severe turbulence downwind of a mountain ridge is often associated with large-amplitude gravity waves that are excited as the air flows over the ridge. Mountain waves can exert an adverse pressure-gradient force on the boundary layer and make it detach from the ground, leading to the formation of atmospheric rotors. However, in a more complex topographic setting, with a second mountain ridge downstream of the first and a valley in between, thermally and dynamically forced processes in the valley (e.g., cold pools or along-valley flow channelling) may be equally important for flow separation. Observations supporting this idea were made during the Terrain-induced Rotor Experiment in Owens Valley (California, USA) in the nighttime hours of 16 April 2006. In that case, an inversion was present in the valley and resultant buoyancy forces appear to have contributed significantly to flow separation well above the valley floor. In an attempt to understand better the thermal and dynamic forces determining this case, numerical simulations with the Weather Research and Forecasting (WRF) Model are run in a nested-domain configuration. The innermost model domain exhibits a horizontal grid spacing of 400 m and a vertical spacing of ~25 m at the ground and spans the southern portion of the Sierra Nevada. The sensitivity of model results (e.g. the valley inversion strength) to the chosen boundary-layer parameterization (e.g., Bougeault-Lacarrère, Mellor-Yamada-Janjic, or Shin-Hong 'scale-aware' PBL schemes) is studied. In a next step, the evaluation of the terms in the momentum equations along the trajectories of separated air parcels will help elucidate the relative importance of pressure-gradient forces and buoyancy forces for flow separation.

  9. Late Quaternary history of southern Chesapeake Bay

    SciTech Connect

    Colman, S.M.; Hobbs, C.H. III; Halka, J.P.

    1985-01-01

    More than 700 km of high-resolution, seismic-reflection profiles and sidescan-sonar images provide new information about the late Quaternary history of southern Chesapeake Bay. Sidescan-sonar images show that, excluding the nearshore zone, most of the bay bottom has a monotonously smooth surface, except that sand waves, ripples, and other bedforms occur in local areas affected by tidal currents. Seismic-reflection data show that the Quaternary stratigraphy of the southern part of the Bay is related primarily to the last cycle of sea-level change. The Quaternary section overlies an erosion surface cut deeply into gently seaward-dipping marine beds of Neogene age. Fluvial paleochannels, related to the last major low sea-level stand, are characterized by as much as 55 m of incision and by thin, irregular, terrace and channel-bottom deposits. Marine and estuarine deposits related to the Holocene transgression partially or fully bury the fluvial valleys and overlie the interfluves. A prominent feature of the Bay-mouth area is a wedge of sediment that has prograded into the Bay from the inner shelf. The common assumption--that the Chesapeake Bay is the drowned valley of the Pleistocene Susquehanna River--is only partially valid for the southern part of the Bay. The Bay mouth area, in general, is relatively young. The axial channel of the Bay is a modern tidal channel that is actively eroding Tertiary deposits and migrating toward the south and west; it is unrelated to older fluvial channels. Also, the positions of the modern axial channel and the last two fluvial paleochannels indicate long-term southward migration of the Bay mouth.

  10. Reconnaissance of Stream Geomorphology, Low Streamflow, and Stream Temperature in the Mountaintop Coal-Mining Region, Southern West Virginia, 1999-2000

    USGS Publications Warehouse

    Wiley, Jeffrey B.; Evaldi, Ronald D.; Eychaner, James H.; Chambers, Douglas B.

    2001-01-01

    The effects of mountaintop removal coal mining and the valley fills created by this mining method in southern West Virginia were investigated by comparing data collected at valley-fill, mined, and unmined sites. Bed material downstream of valley-fill sites had a greater number of particles less than 2 millimeters and a smaller median particle size than the mined and unmined sites. At the 84th percentile of sampled data, however, bed material at each site type had about the same size particles. Bankfull cross-sectional areas at a riffle section were approximately equal at valley-fill and unmined sites, but not enough time has passed and insufficient streamflows since the land was disturbed may have prevented the stream channel at valley-fill sites from reaching equilibrium. The 90-percent flow durations at valley-fill sites generally were 6-7 times greater than at unmined sites. Some valley-fill sites, however, exhibited streamflows similar to unmined sites, and some unmined sites exhibited streamflows similar to valley-fill sites. Daily streamflows from valley-fill sites generally are greater than daily streamflows from unmined sites during periods of low streamflow. Valley-fill sites have a greater percentage of base-flow and a lower percentage of flow from storm runoff than unmined sites. Water temperatures from a valley-fill site exhibited lower daily fluctuations and seasonal variations than water temperatures from an unmined site.

  11. 77 FR 33237 - Saline Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-05

    ... desert valley located in the northwest portion of Death Valley National Park. Despite the variety of... passage of the California Desert Protection Act in 1994. Under NPS management, efforts have been made...

  12. Morphology and downslope sediment displacement in a deep-sea valley, the Valencia Valley (Northwestern Mediterranean)

    USGS Publications Warehouse

    O'Connell, S.; Alonso, B.; Kastens, K.A.; Maldonado, A.; Malinverno, A.; Nelson, C.H.; Palanques, A.; Ryan, William B. F.

    1985-01-01

    The Valencia Valley is a Quaternary, 200 km long deep-sea valley in the Valencia Trough, Western Mediterranean Sea. A swathmapping survey approximately mid-way along the valley length, where the floor has an average gradient of 1:250 (0.2??), shows valley walls that rise 200 to 350 m above the valley floor, with slopes of 2 to 18??. Sediment forming the walls is undergoing retrogressive, upslope-directed slumping with increasing bedding disruption along steeper walls. The valley exhibits a winding course with steep outer and gentler inner walls around bends, and bedforms on the valley floor. Lateral migration around bends is less than 5 km and the valley is deeply entrenched into Quaternary-bedded sediments. ?? 1985 Springer-Verlag New York Inc.

  13. 77 FR 38793 - Grand Valley Rural Power Lines, Inc., Yampa Valley Electric Association, Inc., Intermountain...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... Energy Regulatory Commission Grand Valley Rural Power Lines, Inc., Yampa Valley Electric Association, Inc., Intermountain Rural Electric Association, Tri-State Generation and Transmission Association, Inc. v. Public... Association, Inc., Intermountain Rural Electric Association, and Tri-State Generation and...

  14. Structure of Railroad Valley, Nye County, Nevada

    SciTech Connect

    Ehni, W.J.

    1987-08-01

    In 1976, the second oil field in Nevada - Trap Springs - was discovered in Railroad Valley. Since then, more than 100 oil wells have been drilled in Nye County, and most of these have been in Railroad Valley. This well-control helped to unravel the complex structure of Railroad Valley and enabled the construction of more accurate maps of this valley than any other. This information can be used to construct models for exploring other valleys in the Basin and Range Province of eastern Nevada. The basic stratigraphy of the valley consists of Paleozoic carbonates and shales overlain by Tertiary volcanics, overlain, in turn, by valley fill. The areal extent of Tertiary volcanics, which can be a good reservoir rock, is controlled by tensional normal faulting and paleotopography. In some areas, these volcanics can be in excess of 5000 ft thick, but absent within a few miles, owing to paleotopography and/or faulting. The Paleozoic rocks are deformed by a pre-basin and range compressional history that folded and faulted them. As a result, the structure within the Paleozoics is more complex. Thrust faulting played an important role in the deformation of these rocks. Crystalline basement rocks can be found juxtaposed between Paleozoic outcrops in the flanks of the valley, and Paleozoic rocks found in well control farther out in the valley. The geothermal history of Railroad Valley plays an important role in constructing a structural map of the valley, taking into account the Mesozoic thrust faulting and Tertiary normal faulting. Air photos, combined with good well control and published reports, assist in mapping the geologic structure in Railroad Valley.

  15. California's restless giant: the Long Valley Caldera

    USGS Publications Warehouse

    Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

    2014-01-01

    Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

  16. Trench Logs and Scarp Data from an Investigation of the Steens Fault Zone, Bog Hot Valley and Pueblo Valley, Humboldt County, Nevada

    USGS Publications Warehouse

    Personius, Stephen F.; Crone, Anthony J.; Machette, Michael N.; Kyung, Jai Bok; Cisneros, Hector; Lidke, David J.; Mahan, Shannon

    2006-01-01

    Introduction: This report contains field and laboratory data from a study of the Steens fault zone near Denio, Nev. The 200-km-long Steens fault zone forms the longest, most topographically prominent fault-bounded escarpment in the Basin and Range of southern Oregon and northern Nevada. The down-to-the-east normal fault is marked by Holocene fault scarps along nearly half its length, including the southern one-third of the fault from the vicinity of Pueblo Mountain in southern Oregon to the southern margin of Bog Hot Valley (BHV) southwest of Denio, Nev. We studied this section of the fault to better constrain late Quaternary slip rates, which we hope to compare to deformation rates derived from a recently established geodetic network in the region (Hammond and Thatcher, 2005). We excavated a trench in May 2003 across one of a series of right-stepping fault scarps that extend south from the southern end of the Pueblo Mountains and traverse the floor of Bog Hot Valley, about 4 km south of Nevada State Highway 140. This site was chosen because of the presence of well-preserved fault scarps, their development on lacustrine deposits thought to be suitable for luminescence dating, and the proximity of two geodetic stations that straddle the fault zone. We excavated a second trench in the southern BHV, but the fault zone in this trench collapsed during excavation and thus no information about fault history was documented from this site. We also excavated a soil pit on a lacustrine barrier bar in the southern Pueblo Valley (PV) to better constrain the age of lacustrine deposits exposed in the trench. The purpose of this report is to present photomosaics and trench logs, scarp profiles and slip data, soils data, luminescence and radiocarbon ages, and unit descriptions obtained during this investigation. We do not attempt to use the data presented herein to construct a paleoseismic history of this part of the Steens fault zone; that history will be the subject of a future

  17. Hydrogeologic characteristics of the valley-fill aquifer in the Arkansas River valley, Pueblo County, Colorado

    USGS Publications Warehouse

    Nelson, Gregory A.; Hurr, R.T.; Moore, John E.

    1989-01-01

    The hydrogeology of the valley-fill aquifer of the Arkansas River valley in Pueblo County, Colorado is presented in a series of three maps. The map shows: (1) the altitude and configuration of the bedrock surface beneath the valley-fill material; (2) the altitude and configuration of the water table in the spring of 1966; and (3) the saturation thickness of the valley-fill aquifer in the spring of 1966. (USGS)

  18. Nearly perfect valley filter in silicene.

    PubMed

    Zhang, Qingtian; Chan, K S; Long, Mengqiu

    2016-02-10

    We demonstrate theoretically how a perfect valley filter can be obtained in silicene under the effects of a ferromagnetic stripe and an electric field perpendicular to silicene. A ferromagnetic stripe or an electric field alone can not generate any valley polarization in silicene, but a combination of them can make a perfect valley filter. Two configurations, one with magnetization of the ferromagnetic stripe being perpendicular to the silicene plane and one being parallel to the current direction, are considered. Our proposed device is useful for the realization of a valley beam filter in the development of valleytronic devices.

  19. Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

    USGS Publications Warehouse

    Sweetkind, D.S.; Dickerson, R.P.; Blakely, R.J.; Denning, P.D.

    2001-01-01

    This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3? x 3? area (approximately 70,000 km2) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative. The region transected by the cross sections includes part of the southern Basin and Range Province, the northwest-trending Walker Lane belt, the Death Valley region, and the northern Mojave Desert. The region is structurally complex, where a locally thick Tertiary volcanic and sedimentary section unconformably overlies previously deformed Proterozoic through Paleozoic rocks. All of these rocks have been deformed by complex Neogene ex-tensional normal and strike-slip faults. These cross sections form a three-dimensional network that portrays the interpreted stratigraphic and structural relations in the region; the sections form part of the geologic framework that will be

  20. Hydrogeologic framework and occurrence, movement, and chemical characterization of groundwater in Dixie Valley, west-central Nevada

    USGS Publications Warehouse

    Huntington, Jena M.; Garcia, C. Amanda; Rosen, Michael R.

    2014-01-01

    can be several orders of magnitude more transmissive than surrounding and underlying consolidated rocks and Dixie Valley playa deposits. Transmissivity estimates in the basin fill throughout Dixie Valley ranged from 30 to 45,500 feet squared per day; however, a single transmissivity value of 0.1 foot squared per day was estimated for playa deposits. Groundwater generally flows from the mountain range uplands toward the central valley lowlands and eventually discharges near the playa edge. Potentiometric contours east and west of the playa indicate that groundwater is moving eastward from the Stillwater Range and westward from the Clan Alpine Mountains toward the playa. Similarly, groundwater flows from the southern and northern basin boundaries toward the basin center. Subsurface groundwater flow likely enters Dixie Valley from Fairview and Stingaree Valleys in the south and from Jersey and Pleasant Valleys in the north, but groundwater connections through basin-fill deposits were present only across the Fairview and Jersey Valley divides. Annual subsurface inflow from Fairview and Jersey Valleys ranges from 700 to 1,300 acre-feet per year and from 1,800 to 2,300 acre-feet per year, respectively. Groundwater flow between Dixie, Stingaree, and Pleasant Valleys could occur through less transmissive consolidated rocks, but only flow through basin fill was estimated in this study. Groundwater in the playa is distinct from the freshwater, basin-fill aquifer. Groundwater mixing between basin-fill and playa groundwater systems is physically limited by transmissivity contrasts of about four orders of magnitude. Total dissolved solids in playa deposit groundwater are nearly 440 times greater than total dissolved solids in the basin-fill groundwater. These distinctive physical and chemical flow restrictions indicate that groundwater interaction between the basin fill and playa sediments was minimal during this study period (water years 2009–11). Groundwater in Dixie Valley

  1. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described..., “Green Valley of Russian River Valley” is a term of viticultural significance. “Sonoma County...

  2. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described..., “Green Valley of Russian River Valley” is a term of viticultural significance. “Sonoma County...

  3. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area described..., “Green Valley of Russian River Valley” is a term of viticultural significance. “Sonoma County...

  4. Origin and character of loesslike silt in the southern Qinghai-Xizang (Tibet) Plateau, China

    USGS Publications Warehouse

    Pewe, T.L.; Tungsheng, Liu; Slatt, R.M.; Bingyuan, Li

    1995-01-01

    Retransported, tan, loesslike silt is widespread in the southern Qinghai-Xizang (Tibet) Plateau. The silt occurs mainly in the lowlands and lower slopes and is absent on steep slopes and active flood plains. The silt covers most alluvial fans and is interbedded with the sand and gravel of the fans. It is well exposed in the agricultural fields on low terraces in the valleys and in the steep-walled scarps of dissected valley fill. The silt is primary loess on the low hill tops; however, the poorly to well-stratified loesslike silt on the lower slopes and in valley bottoms of the major river valleys is retransported loess. It probably was originally deposited by winds blowing across broad vegetation-free flood plains.

  5. Rift Valley fever during rainy seasons, Madagascar, 2008 and 2009.

    PubMed

    Andriamandimby, Soa Fy; Randrianarivo-Solofoniaina, Armand Eugène; Jeanmaire, Elisabeth M; Ravololomanana, Lisette; Razafimanantsoa, Lanto Tiana; Rakotojoelinandrasana, Tsanta; Razainirina, Josette; Hoffmann, Jonathan; Ravalohery, Jean-Pierre; Rafisandratantsoa, Jean-Théophile; Rollin, Pierre E; Reynes, Jean-Marc

    2010-06-01

    During 2 successive rainy seasons, January 2008 through May 2008 and November 2008 through March 2009, Rift Valley fever virus (RVFV) caused outbreaks in Madagascar. Human and animal infections were confirmed on the northern and southern coasts and in the central highlands. Analysis of partial sequences from RVFV strains showed that all were similar to the strains circulating in Kenya during 2006-2007. A national cross-sectional serologic survey among slaughterhouse workers at high risk showed that RVFV circulation during the 2008 outbreaks included all of the Malagasy regions and that the virus has circulated in at least 92 of Madagascar's 111 districts. To better predict and respond to RVF outbreaks in Madagascar, further epidemiologic studies are needed, such as RVFV complete genome analysis, ruminant movement mapping, and surveillance implementation.

  6. Kinematics at the Intersection of the Garlock and Death Valley Fault Zones, California: Integration of TM Data and Field Studies

    NASA Technical Reports Server (NTRS)

    Verosub, Kenneth L.; Brady, Roland H., III; Abrams, Michael

    1989-01-01

    Kinematic relationships at the intersection of the southern Death Valley and Garlock fault zones were examined to identify and delineate the eastern structural boundary between the Mojave and the Basin and Range geologic terrains, and to construct a model for the evolution of this boundary through time. In order to accomplish this, satellite imagery was combined with field investigations to study six areas in the vicinity of the intersection, or possible extensions, of the fault zones. The information gathered from these areas allows the test of various hypotheses that were proposed to explain the interaction between the Death Valley and Garlock fault zones.

  7. North Valley/South Valley Survey--Perceptions of Utah Valley State College and the Need for a Branch Campus.

    ERIC Educational Resources Information Center

    Jacobs, Bart R.

    Utah Valley Community College became Utah Valley State College (UVSC) in 1993, due to the increasing need for a four-year, degree-granting institution in Utah County. UVSC now offers 21 four-year programs, and enrollment has been growing at an average rate of 8% per year since 1986. There were 20,946 students enrolled for fall term 2000, and…

  8. Liquefaction sites, Imperial Valley, California.

    USGS Publications Warehouse

    Youd, T.L.; Bennett, M.J.

    1983-01-01

    Sands that did and did not liquefy at two sites during the 1979 Imperial Valley, Calif., earthquake (ML = 6.6) are identified and their properties evaluated. SPT tests were used to evaluate liquefaction susceptibility. Loose fine sands in an abandoned channel liquefied and produced sand boils, ground fissures, and a lateral spread at the Heber Road sites. Evidence of liquefaction was not observed over moderately dense over-bank sand east of the channel nor over dense point-bar sand to the west. -from ASCE Publications Information

  9. Work through the valley: plan.

    PubMed

    Jones, Loretta; Meade, Barbara; Koegel, Paul; Lucas-Wright, Aziza; Young-Brinn, Angela; Terry, Chrystene; Norris, Keith

    2009-01-01

    This first of three chapters on the Valley stage, or main work of a Community-Partnered Participatory Research (CPPR) initiative, concerns the planning phase of the work cycle. The main goal of this phase is to develop an action plan, which clarifies the goals, methods, responsible individuals, and timeline for doing the work. Further, this chapter reviews approaches, such as creativity and use of humor, that help level the playing field and assure community co-leadership with academic partners in developing effective action plans.

  10. Aquaculture in the Imperial Valley -- A geothermal success story

    SciTech Connect

    Rafferty, K.

    1999-03-01

    The Salton Sea and Imperial Valley area of southern California has long been recognized as a hot spot of geothermal development. In the geothermal industry, this area has for some time been synonymous with electric power generation projects. Starting with the first plant in East Mesa in 1979, geothermal power has increased over the years to the present 400+ MW of installed capacity in the three primary areas of Salton Sea, Heber and East Mesa. Although most in the industry are aware of the millions of kilowatt-hours annually produced in this desert oasis of development, they remain surprisingly uninformed about the Valley`s other geothermal industry -- aquaculture. At present, there are approximately 15 fish farming (or aquaculture) operations clustered, for the most part, around the Salton Sea. All of these farms use geothermal fluids to control the temperature of the fish culture facilities so as to produce larger fish in a shorter period of time and to permit winter production which would otherwise not be possible. In aggregate, these farms produce on the order of 10,000,000 lbs of fish per year most of which is sold into the California market. Principle species are catfish, striped bass and tilapia. For the past several years, tilapia has been the fastest growing part of the aquaculture industry. In 1996, the total US consumption of tilapia was 62,000 lbs. Of this, only 16,000,000 lbs (26%) was domestically produced and the balance imported. The primary market for the fish on the West Coast is among the Asian-American populations in the major cities. Fish are shipped and sold liver at the retail level.

  11. Geologic history of the Yosemite Valley

    USGS Publications Warehouse

    Matthes, Francois E.

    1930-01-01

    Projection of the longitudinal profiles of these hanging valleys forward to the axis of the Merced Canyon shows that they are closely accordant in height. Their profiles indicate a series of points on a former profile of the Merced with respect to which the side streams had graded their courses prior to the last uplift. This old profile can be extended upward into the glaciated part of the Merced Canyon above El Portal and even into the profoundly glaciated Yosemite Valley, accordant points being furnished by a number of hanging side valleys (due allowance being made for glacial erosion suffered by those valleys). However, not all the hanging valleys of the Yosemite region are accordant with this set. Several of them, including the upland valley of Yosemite Creek, constitute a separate set indicating another old profile of the Merced at a level 600 to 1,000 feet higher than the first. Others, including the hanging gulch of lower Bridalveil Creek, point to an old profile of the Merced about 1,200 feet lower than the first. There are thus three distinct sets of hanging valleys produced in three cycles of stream erosion. The valleys of the upper set, like those of the middle set, were left hanging as a result of rapid trenching by the Merced induced by an uplift of the range, there having been two such uplifts. Only the valleys of the lower set hang because of glacial deepening and widening of the Yosemite Valley, the cycle in which they were cut having been interrupted by the advent of the Pleistocene glaciers. They consequently indicate the preglacial depth of the Yosemite Valley. That depth, measured from the brow of El Capitan, was about 2,400 feet; measured from the rim at Glacier Point it was about 2,000 feet.

  12. Modeling Events in the Lower Imperial Valley Basin

    NASA Astrophysics Data System (ADS)

    Tian, X.; Wei, S.; Zhan, Z.; Fielding, E. J.; Helmberger, D. V.

    2010-12-01

    The Imperial Valley below the US-Mexican border has few seismic stations but many significant earthquakes. Many of these events, such as the recent El Mayor-Cucapah event, have complex mechanisms involving a mixture of strike-slip and normal slip patterns with now over 30 aftershocks with magnitude over 4.5. Unfortunately, many earthquake records from the Southern Imperial Valley display a great deal of complexity, ie., strong Rayleigh wave multipathing and extended codas. In short, regional recordings in the US are too complex to easily separate source properties from complex propagation. Fortunately, the Dec 30 foreshock (Mw=5.9) has excellent recordings teleseismically and regionally, and moreover is observed with InSAR. We use this simple strike-slip event to calibrate paths. In particular, we are finding record segments involving Pnl (including depth phases) and some surface waves (mostly Love waves) that appear well behaved, ie., can be approximated by synthetics from 1D local models and events modeled with the Cut-and-Paste (CAP) routine. Simple events can then be identified along with path calibration. Modeling the more complicated paths can be started with known mechanisms. We will report on both the aftershocks and historic events.

  13. Biostratigraphy of marine Pliocene-Pleistocene deposits, Simi Valley, California

    SciTech Connect

    Groves, L.T.; Squires, R.L.

    1988-03-01

    Richly fossiliferous, marine deltaic deposits exposed in the northern Simi Valley, southern California, are important biostratigraphically because they straddle the Pliocene-Pleistocene boundary. These deposits consist of fine to coarse-grained sandstone with interbedded conglomerate. The best exposure is in Gilibrand Quarry, where 250 m are exposed in a continuous section with four main fossiliferous zones rich in mollusks. Most of these mollusks are complete and display growth series that represent a life assemblage with minimal postmortem transport. An erosional surface is present between the second and third fossiliferous beds in the quarry. Beds below the erosional surface contain mollusks indicative of Pliocene age. These mollusks are the pectinid Patinopecten healeyi and the epitoniid gastropod Opalia varicostata. Beds above the erosional surface contain a calcareous nannofossil assemblage that suggests a Pleistocene age. These species are Coccolithus pelagicus, Helicosphaera carteri, and Dictyococcites productus. (An absence of discoaster species and Emiliana huxleyi would place this assemblage in the early or medial Pleistocene.) The name lower Saugus Formation is assigned to all of these marine Pliocene-Pleistocene deposits because W.S. W. Kew in 124 originally named and mapped these strata as Saugus Formation. Confusion will be avoided by discontinuing usage of the names Fernando Formation, Pico Formation, and Sunshine Ranch Member of the Saugus Formation in this area for these strata. The lower Saugus Formation in the Simi Valley is faunally similar and time-correlate with the San Diego Formation in San Diego County.

  14. Audiomagnetotelluric investigation of Snake Valley, eastern Nevada and western Utah

    USGS Publications Warehouse

    McPhee, Darcy K.; Pari, Keith; Baird, Frank

    2009-01-01

    As support for an exploratory well-drilling and hydraulic-testing program, AMT data were collected using a Geometrics Stratagem EH4 system along four profiles that extend roughly east-west from the southern Snake Range into Snake Valley. The profiles range from 3 to 5 kilometers in length, and station spacing was 200 to 400 meters. Two-dimensional inverse models were computed using the data from the transverse-electric (TE), transverse-magnetic (TM), and combined (TE+TM) mode using a conjugate gradient, finite-difference method. Interpretation of the 2-D AMT models defines several faults, some of which may influence ground-water flow in the basins, as well as identify underlying Paleozoic carbonate and clastic rocks and the thickness of basin-fill sediments. These AMT data and models, coupled with the geologic mapping and other surface geophysical methods, form the basis for identifying potential well sites and defining the subsurface structures and stratigraphy within Snake Valley.

  15. A respiratory alert model for the Shenandoah Valley, Virginia, USA.

    PubMed

    Hondula, David M; Davis, Robert E; Knight, David B; Sitka, Luke J; Enfield, Kyle; Gawtry, Stephen B; Stenger, Phillip J; Deaton, Michael L; Normile, Caroline P; Lee, Temple R

    2013-01-01

    Respiratory morbidity (particularly COPD and asthma) can be influenced by short-term weather fluctuations that affect air quality and lung function. We developed a model to evaluate meteorological conditions associated with respiratory hospital admissions in the Shenandoah Valley of Virginia, USA. We generated ensembles of classification trees based on six years of respiratory-related hospital admissions (64,620 cases) and a suite of 83 potential environmental predictor variables. As our goal was to identify short-term weather linkages to high admission periods, the dependent variable was formulated as a binary classification of five-day moving average respiratory admission departures from the seasonal mean value. Accounting for seasonality removed the long-term apparent inverse relationship between temperature and admissions. We generated eight total models specific to the northern and southern portions of the valley for each season. All eight models demonstrate predictive skill (mean odds ratio = 3.635) when evaluated using a randomization procedure. The predictor variables selected by the ensembling algorithm vary across models, and both meteorological and air quality variables are included. In general, the models indicate complex linkages between respiratory health and environmental conditions that may be difficult to identify using more traditional approaches. PMID:22438053

  16. Timing and new geomorphologic evidence of the last deglaciation stages in Sierra Nevada (southern Spain)

    NASA Astrophysics Data System (ADS)

    Palacios, David; Gómez-Ortiz, Antonio; Andrés, Nuria; Salvador, Ferrán; Oliva, Marc

    2016-10-01

    The main objective of this research is to improve knowledge of the deglaciation stages in Sierra Nevada (southern Spain) by applying 36Cl cosmogenic exposure dating to 28 samples from moraine and fossil rock glacier boulders and glacial polished surfaces, in 5 glaciated valleys around Veleta Peak (3396 m asl; 37°03‧02″N 3°20‧54″W). The results show that shortly before the Last Glacial Maximum (LGM) and during the LGM, the heads of the glacial valleys were occupied by ice tongues, with possible glacial transfluence between the valleys. After 19 ka, a major glacial regression started, but glaciers during the Oldest Dryas (OD) expanded again and refilled the valley bottoms. The glacial advances of the pre-LGM, LGM and OD formed polygenic moraine systems. During the Bølling-Allerød the glaciers receded and probably disappeared. Thereafter, the valley bottoms remained ice-free. During the Younger Dryas (YD) small glaciers developed again, but only in cirques shaped on east-facing slopes. Subsequently, these glaciers started retreating towards their valley heads and finally disappeared completely. With the onset of the Holocene, rock glaciers developed inside the deglaciated cirques on the eastern slopes of some valleys, but only under the most active and protected headwalls did large complex rock glaciers develop and remained active until the mid-Holocene.

  17. 1. ELEVATION OF BUILDING 223, LOOKING EASTNORTHEAST. Mill Valley ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ELEVATION OF BUILDING 223, LOOKING EAST-NORTHEAST. - Mill Valley Air Force Station, Civil Engineering Administration Office, East Ridgecrest Boulevard, Mount Tamalpais, Mill Valley, Marin County, CA

  18. Valley-dependent band structure and valley polarization in periodically modulated graphene

    NASA Astrophysics Data System (ADS)

    Lu, Wei-Tao

    2016-08-01

    The valley-dependent energy band and transport property of graphene under a periodic magnetic-strained field are studied, where the time-reversal symmetry is broken and the valley degeneracy is lifted. The considered superlattice is composed of two different barriers, providing more degrees of freedom for engineering the electronic structure. The electrons near the K and K' valleys are dominated by different effective superlattices. It is found that the energy bands for both valleys are symmetric with respect to ky=-(AM+ξ AS) /4 under the symmetric superlattices. More finite-energy Dirac points, more prominent collimation behavior, and new crossing points are found for K' valley. The degenerate miniband near the K valley splits into two subminibands and produces a new band gap under the asymmetric superlattices. The velocity for the K' valley is greatly renormalized compared with the K valley, and so we can achieve a finite velocity for the K valley while the velocity for the K' valley is zero. Especially, the miniband and band gap could be manipulated independently, leading to an increase of the conductance. The characteristics of the band structure are reflected in the transmission spectra. The Dirac points and the crossing points appear as pronounced peaks in transmission. A remarkable valley polarization is obtained which is robust to the disorder and can be controlled by the strain, the period, and the voltage.

  19. 27 CFR 9.153 - Redwood Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Redwood Valley. 9.153 Section 9.153 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.153 Redwood Valley. (a) Name. The name of...

  20. 27 CFR 9.191 - Ramona Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Approved Maps. The two United States Geological Survey 1:100,000 scale topographic (30 × 60 Minute Quadrangle) maps used to determine the boundaries of the Ramona Valley viticultural area are titled— (1) Borrego Valley, California, 1982 edition; and (2) El Cajon, California, 1979 edition. (c) Boundary....

  1. 27 CFR 9.176 - Capay Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...”. (b) Approved maps. The appropriate map for determining the boundary of the Capay Valley viticultural area is the United States Geological Survey (U.S.G.S.) topographic map titled: 30X60 Minute Quadrangle (Healdsburg, California 1972) (Scale: 1:100,000). (c) Boundaries. The Capay Valley viticultural area...

  2. Valley Pearl’ table grape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Valley Pearl’ is an early to mid-season, white seedless table grape (Vitis vinifera L.) suitable for commercial table grape production where V. vinifera can be grown. Significant characteristics of ‘Valley Pearl’ are its high and consistent fruit production on spur pruned vines and large round berr...

  3. Illinois Valley Industry Retention Program. Final Report.

    ERIC Educational Resources Information Center

    Allen, John P.

    The Illinois Valley Industry Retention Program was conceived with the goals of retaining existing industries in the area and saving presently available jobs for the area's citizens. A program committee, formed in March 1982 of representatives from state government, Illinois Valley Community College (IVCC), and local businesses, undertook a survey…

  4. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultural area described in this section is “Knights Valley... viticultural area are four U.S.G.S. maps. They are— (1) “Mount St. Helena Quadrangle, California,” 7.5...

  5. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultural area described in this section is “Knights Valley... viticultural area are four U.S.G.S. maps. They are— (1) “Mount St. Helena Quadrangle, California,” 7.5...

  6. 27 CFR 9.45 - Suisun Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.45 Suisun Valley. (a) Name. The name of the viticultural area described in this section is “Suisun Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Mt. George Quadrangle, California”, 7.5...

  7. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultural area described in this section is “Knights Valley... viticultural area are four U.S.G.S. maps. They are— (1) “Mount St. Helena Quadrangle, California,” 7.5...

  8. 27 CFR 9.38 - Cienega Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.38 Cienega Valley. (a) Name. The name of the viticultural area described in this section is “Cienega Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Hollister Quadrangle, California,” 7.5...

  9. 27 CFR 9.45 - Suisun Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.45 Suisun Valley. (a) Name. The name of the viticultural area described in this section is “Suisun Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Mt. George Quadrangle, California”, 7.5...

  10. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultural area described in this section is “Knights Valley... viticultural area are four U.S.G.S. maps. They are— (1) “Mount St. Helena Quadrangle, California,” 7.5...

  11. 27 CFR 9.76 - Knights Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.76 Knights Valley. (a) Name. The name of the viticultural area described in this section is “Knights Valley... viticultural area are four U.S.G.S. maps. They are— (1) “Mount St. Helena Quadrangle, California,” 7.5...

  12. 27 CFR 9.45 - Suisun Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.45 Suisun Valley. (a) Name. The name of the viticultural area described in this section is “Suisun Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Mt. George Quadrangle, California”, 7.5...

  13. 27 CFR 9.45 - Suisun Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.45 Suisun Valley. (a) Name. The name of the viticultural area described in this section is “Suisun Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Mt. George Quadrangle, California”, 7.5...

  14. 27 CFR 9.38 - Cienega Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.38 Cienega Valley. (a) Name. The name of the viticultural area described in this section is “Cienega Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Hollister Quadrangle, California,” 7.5...

  15. 27 CFR 9.45 - Suisun Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.45 Suisun Valley. (a) Name. The name of the viticultural area described in this section is “Suisun Valley... viticultural area are four U.S.G.S. maps. They are titled: (1) “Mt. George Quadrangle, California”, 7.5...

  16. Detection and Response for Rift Valley fever

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rift Valley fever is a viral disease that impacts domestic livestock and humans in Africa and the Middle East, and poses a threat to military operations in these areas. We describe a Rift Valley fever Risk Monitoring website, and its ability to predict risk of disease temporally and spatially. We al...

  17. Model Program: Conestoga Valley School District, PA

    ERIC Educational Resources Information Center

    Litowitz, Len S.

    2007-01-01

    This article features the Conestoga Valley School District and its Technology Education program. Conestoga Valley, which is located in historic Lancaster County, Pennsylvania, covers 56 square miles comprising a population of approximately 29,000 people in an area that is best described as agricultural and rural-residential. Situated near the…

  18. Boulder Valley Schools Teen Parenting Program.

    ERIC Educational Resources Information Center

    Parmerlee-Greiner, Gloria

    To meet the needs of pregnant and parenting adolescents in Boulder Valley (Colorado), the local public school district has developed the Boulder Valley Schools Teen Parenting Program, now in its 12th year. The program was designed to help teen parents to mature to meet the challenges of parenting, enhance the school district's dropout/intervention…

  19. 27 CFR 9.174 - Yadkin Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Yadkin Valley. 9.174... Yadkin Valley. (a) Name. The name of the viticultural area described in this section is “Yadkin Valley”. (b) Approved maps. The appropriate maps for determining the boundaries of the Yadkin...

  20. 27 CFR 9.174 - Yadkin Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Yadkin Valley. 9.174... Yadkin Valley. (a) Name. The name of the viticultural area described in this section is “Yadkin Valley”. (b) Approved maps. The appropriate maps for determining the boundaries of the Yadkin...

  1. 27 CFR 9.174 - Yadkin Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Yadkin Valley. 9.174... Yadkin Valley. (a) Name. The name of the viticultural area described in this section is “Yadkin Valley”. (b) Approved maps. The appropriate maps for determining the boundaries of the Yadkin...

  2. 27 CFR 9.174 - Yadkin Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Yadkin Valley. 9.174... Yadkin Valley. (a) Name. The name of the viticultural area described in this section is “Yadkin Valley”. (b) Approved maps. The appropriate maps for determining the boundaries of the Yadkin...

  3. 27 CFR 9.174 - Yadkin Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Yadkin Valley. 9.174... Yadkin Valley. (a) Name. The name of the viticultural area described in this section is “Yadkin Valley”. (b) Approved maps. The appropriate maps for determining the boundaries of the Yadkin...

  4. Atmospheric dispersion in mountain valleys and basins

    SciTech Connect

    Allwine, K.J.

    1992-01-01

    The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ``ventilation rate`` of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

  5. Atmospheric dispersion in mountain valleys and basins

    SciTech Connect

    Allwine, K.J.

    1992-01-01

    The primary goal of the research is to further characterize and understand dispersion in valley and basin atmospheres. A secondary, and related goal, is to identify and understand the dominant physical processes governing this dispersion. This has been accomplished through a review of the current literature, and analyses of recently collected data from two field experiments. This work should contribute to an improved understanding of material transport in the atmospheric boundary layer. It was found that dispersion in a freely draining valley (Brush Creek valley, CO) atmosphere is much greater than in an enclosed basin (Roanoke, VA) atmosphere primarily because of the greater wind speeds moving past the release point and the greater turbulence levels. The development of a cold air pool in the Roanoke basin is the dominant process governing nighttime dispersion in the basin, while the nighttime dispersion in the Brush Creek valley is dominated by turbulent diffusion and plume confinement between the valley sidewalls. The interaction between valley flows and above ridgetops flows is investigated. A ventilation rate'' of material transport between the valley and above ridgetop flows is determined. This is important in regional air pollution modeling and global climate modeling. A simple model of dispersion in valleys, applicable through a diurnal cycle, is proposed.

  6. The San Joaquin Valley: 20 years later

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The history of irrigation development and the need for disposal of saline drainage water in the San Joaquin Valley was described to provide background for the drainage water disposal problem that resulted from the closure of the Kesterson Reservoir. A 5 year study developed in Valley alternatives fo...

  7. Beaver assisted river valley formation

    USGS Publications Warehouse

    Westbrook, C.J.; Cooper, D.J.; Baker, B.W.

    2011-01-01

    We examined how beaver dams affect key ecosystem processes, including pattern and process of sediment deposition, the composition and spatial pattern of vegetation, and nutrient loading and processing. We provide new evidence for the formation of heterogeneous beaver meadows on riverine system floodplains and terraces where dynamic flows are capable of breaching in-channel beaver dams. Our data show a 1.7-m high beaver dam triggered overbank flooding that drowned vegetation in areas deeply flooded, deposited nutrient-rich sediment in a spatially heterogeneous pattern on the floodplain and terrace, and scoured soils in other areas. The site quickly de-watered following the dam breach by high stream flows, protecting the deposited sediment from future re-mobilization by overbank floods. Bare sediment either exposed by scouring or deposited by the beaver flood was quickly colonized by a spatially heterogeneous plant community, forming a beaver meadow. Many willow and some aspen seedlings established in the more heavily disturbed areas, suggesting the site may succeed to a willow carr plant community suitable for future beaver re-occupation. We expand existing theory beyond the beaver pond to include terraces within valleys. This more fully explains how beavers can help drive the formation of alluvial valleys and their complex vegetation patterns as was first postulated by Ruedemann and Schoonmaker in 1938. ?? 2010 John Wiley & Sons, Ltd.

  8. Water resources of the Rincon and Mesilla Valleys and adjacent areas, New Mexico

    USGS Publications Warehouse

    Wilson, Clyde A.; White, Robert R.; Orr, Brennon R.; Roybal, R. Gary

    1981-01-01

    valleys in the adjacent upland areas. Ground water moves southeastward beneath the West Mesa area, converging with ground-water flow in the southern end of the Mesilla Valley. Good hydraulic connection exists between sediments of the West Mesa and Mesilla Valley areas. Ground water in the southern end of the Jornada del Muerto moves generally to the northwest, converges with south-flowing ground water near Point of Rocks, and moves westward into Rincon Valley sediments near Rincon. A small amount of ground water flows westward from the southern end of the Jornada del Muerto across a subsurface igneous body into the Mesilla Valley. Ground-water discharge occurs throughout the Rincon and Mesilla Valleys as drain flow to the river and evapotranspiration. Dissolved-solids concentrations in the water in the flood-plain alluvium of the Rincon and Mesilla Valleys are generally greater than 1,000 milligrams per liter. A freshwater zone, with dissolved-solids concentrations less than 1,000 milligrams per liter, underlies this thin, slightly saline zone beneath much of the Mesilla Valley. This freshwater zone, occurring in the Santa Fe Group, is surrounded by saline water. Within the study area, major dissolved ions in ground water include sodium, calcium, bicarbonate, and sulfate. The Rio Grande is a gainlng stream in the northern parts of the Rincon and Mesilla Valleys and a losing stream in the southern part of the Mesilla Valley. Gains and losses result from a close interconnection with ground-water flow systems. Large surface-water irrigation allotments increase ground-water recharge. Increased recharge raises ground-water levels and improves shallow ground-water quality adjacent to these recharge areas. Shallow ground-water discharges to drains, which flow into the Rio Grande. Dissolved-solids concentrations in the Rio Grande increase by as much as 60 percent between Caballo Reservoir and the southern end of the study area.

  9. Valley Vortex States in Sonic Crystals

    NASA Astrophysics Data System (ADS)

    Lu, Jiuyang; Qiu, Chunyin; Ke, Manzhu; Liu, Zhengyou

    2016-03-01

    Valleytronics is quickly emerging as an exciting field in fundamental and applied research. In this Letter, we study the acoustic version of valley states in sonic crystals and reveal a vortex nature of such states. In addition to the selection rules established for exciting valley polarized states, a mimicked valley Hall effect of sound is proposed further. The extraordinary chirality of valley vortex states, detectable in experiments, may open a new possibility in sound manipulations. This is appealing to scalar acoustics that lacks a spin degree of freedom inherently. In addition, the valley selection enables a handy way to create vortex matter in acoustics, in which the vortex chirality can be controlled flexibly. Potential applications can be anticipated with the exotic interaction of acoustic vortices with matter, such as to trigger the rotation of the trapped microparticles without contact.

  10. The Long Valley Caldera GIS database

    USGS Publications Warehouse

    Battaglia, Maurizio; Williams, M.J.; Venezky, D.Y.; Hill, D.P.; Langbein, J.O.; Farrar, C.D.; Howle, J.F.; Sneed, M.; Segall, P.

    2003-01-01

    This database provides an overview of the studies being conducted by the Long Valley Observatory in eastern California from 1975 to 2001. The database includes geologic, monitoring, and topographic datasets related to Long Valley caldera. The CD-ROM contains a scan of the original geologic map of the Long Valley region by R. Bailey. Real-time data of the current activity of the caldera (including earthquakes, ground deformation and the release of volcanic gas), information about volcanic hazards and the USGS response plan are available online at the Long Valley observatory web page (http://lvo.wr.usgs.gov). If you have any comments or questions about this database, please contact the Scientist in Charge of the Long Valley observatory.

  11. Groundwater quality in the Monterey Bay and Salinas Valley groundwater basins, California

    USGS Publications Warehouse

    Kulongoski, Justin T.; Belitz, Kenneth

    2011-01-01

    The Monterey-Salinas study unit is nearly 1,000 square miles and consists of the Santa Cruz Purisima Formation Highlands, Felton Area, Scotts Valley, Soquel Valley, West Santa Cruz Terrace, Salinas Valley, Pajaro Valley, and Carmel Valley groundwater basins (California Department of Water Resources, 2003; Kulongski and Belitz, 2011). These basins were grouped into four study areas based primarily on geography. Groundwater basins in the north were grouped into the Santa Cruz study area, and those to the south were grouped into the Monterey Bay, the Salinas Valley, and the Paso Robles study areas (Kulongoski and others, 2007). The study unit has warm, dry summers and cool, moist winters. Average annual rainfall ranges from 31 inches in Santa Cruz in the north to 13 inches in Paso Robles in the south. The study areas are drained by several rivers and their principal tributaries: the Salinas, Pajaro, and Carmel Rivers, and San Lorenzo Creek. The Salinas Valley is a large intermontane valley that extends southeastward from Monterey Bay to Paso Robles. It has been filled, up to a thickness of 2,000 feet, with Tertiary and Quaternary marine and terrestrial sediments that overlie granitic basement. The Miocene-age Monterey Formation and Pliocene- to Pleistocene-age Paso Robles Formation, and Pleistocene to Holocene-age alluvium contain freshwater used for supply. The primary aquifers in the study unit are defined as those parts of the aquifers corresponding to the perforated intervals of wells listed in the California Department of Public Health database. Public-supply wells are typically drilled to depths of 200 to 650 feet, consist of solid casing from the land surface to depths of about 175 to 500 feet, and are perforated below the solid casing. Water quality in the primary aquifers may differ from that in the shallower and deeper parts of the aquifer system. Groundwater movement is generally from the southern part of the Salinas Valley north towards the Monterey Bay

  12. Erosional valleys in the Thaumasia region of Mars: Hydrothermal and seismic origins

    USGS Publications Warehouse

    Tanaka, K.L.; Dohm, J.M.; Lias, J.H.; Hare, T.M.

    1998-01-01

    Analysis of erosional valleys, geologic materials and features, and topography through time in the Thaumasia region of Mars using co-registered digital spatial data sets reveals significant associations that relate to valley origin. Valleys tend to originate (1) on Noachian to Early Hesperian (stages 1 and 2) large volcanoes, (2) within 50-100 km of stages 1 and 2 rift systems, and (3) within 100 km of Noachian (stage 1) impact craters >50 km in diameter. These geologic preferences explain observations of higher valley-source densities (VSDs) in areas of higher elevations and regional slopes (>1??) because the volcanoes, rifts, and craters form high, steep topography or occur in terrain of high relief. Other stage 1 and stage 2 high, steep terrains, however, do not show high VSDs. The tendency for valleys to concentrate near geologic features and the overall low drainage densities in Thaumasia compared to terrestrial surfaces rule out widespread precipitation as a major factor in valley formation (as is proposed in wann, wet climate scenarios) except perhaps during the Early Noachian, for which much of the geologic record has been obliterated. Instead, volcanoes and rifts may indicate the presence of shallow crustal intrusions that could lead to local hydrothermal circulation, melting of ground ice and snow, and groundwater sapping. However, impact-crater melt would provide a heat source at the surface that might drive away water, forming valleys in the process. Post-stage 1 craters mostly have low nearby VSDs, which, for valleys incised in older rocks, suggests burial by e??jecta and, for . younger valleys, may indicate desiccation of near-surface water and deepening of the cryosphere. Later Hesperian and Amazonian (stages 3 and 4) valleys originate within 100-200 km of three young, large impact craters and near rifts systems at Warrego Valle??s and the southern part of Coprates rise. These valleys likely developed when the cryosphere was a couple kilometers or

  13. Ground-water conditions and storage capacity in the San Joaquin Valley, California

    USGS Publications Warehouse

    Davis, G.H.; Green, J.H.; Olmsted, F.H.; Brown, D.W.

    1959-01-01

    The San Joaquin Valley includes roughly the southern two-thirds of the Great Central Valley of California. It is a broad structural trough surrounded by mountains. The northern part of the valley drains through the San Joaquin River northward to San Francisco Bay ; the southern part of the valley normally is a basin of interior drainage tributary to evaporation sumps in the trough of the valley, chiefly Tulare and Buena Vista Lake beds. In years of normal discharge most of the streamflow in the southern part of the valley not diverted for irrigation finds its way to Tulare and Buena Vista Lake beds. In the historic past, however, during years of heavy floods the low divide between Buena Vista and Tulare Lakes and the low divide between Tulare Lake and the San Joaquin River were overtopped and through-flowing drainage occurred over the full length of the valley. Because the Tulare Lake bed is the lowest point and also the largest sump, this whole basin of interior drainage is commonly referred to as the Tulare Lake drainage basin. Average annual precipitation ranges from more than 15 inches in the north- eastern part of the valley to less than 4 inches in the southwestern part. The precipitation decreases from north to south and from east to west across the valley. Streamflow, the critical quantity in the water supply, depends almost wholly on the amount and distribution of precipitation in the Sierra Nevada to the east. Much of this precipitation falls as snow, and the snowpack acts as a natural reservoir retaining much of the annual runoff until late spring and early summer. The mean seasonal runoff to the San Joaquin Valley is nearly 10 million acre- feet, of which about two-thirds is tributary to the San Joaquin River; the remaining third is tributary to Tulare Lake drainage basin. In 1952 about 8.5 million acre-feet of surface water was diverted for irrigation. Withdrawals of ground water for irrigation in 1952 approximated 7.5 million acre-feet. The surface of

  14. Water availability and land subsidence in the Central Valley, California, USA

    USGS Publications Warehouse

    Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

    2016-01-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  15. Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada

    USGS Publications Warehouse

    Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.

    2016-01-22

    This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute Mesa, an area of historical underground nuclear testing at the Nevada National Security Site, are believed to be migrating toward Oasis Valley. Delineating the boundary of the PMOV groundwater basin is necessary to adequately assess the potential for transport of radionuclides from Pahute Mesa to Oasis Valley.The PMOV contributing area is defined based on regional water-level contours, geologic controls, and knowledge of adjacent flow systems. The viability of this area as the contributing area to Oasis Valley and the absence of significant interbasin flow between the PMOV groundwater basin and adjacent basins are shown regionally and locally. Regional constraints on the location of the contributing area boundary and on the absence of interbasin groundwater flow are shown by balancing groundwater discharges in the PMOV groundwater basin and adjacent basins against available water from precipitation. Internal consistency for the delineated contributing area is shown by matching measured water levels, groundwater discharges, and transmissivities with simulated results from a single-layer, steady-state, groundwater-flow model. An alternative basin boundary extending farther north than the final boundary was rejected based on a poor chloride mass balance and a large imbalance in the northern area between preferred and simulated recharge.

  16. Water availability and land subsidence in the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

    2016-05-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  17. Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada

    USGS Publications Warehouse

    Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.

    2016-01-01

    This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute Mesa, an area of historical underground nuclear testing at the Nevada National Security Site, are believed to be migrating toward Oasis Valley. Delineating the boundary of the PMOV groundwater basin is necessary to adequately assess the potential for transport of radionuclides from Pahute Mesa to Oasis Valley.The PMOV contributing area is defined based on regional water-level contours, geologic controls, and knowledge of adjacent flow systems. The viability of this area as the contributing area to Oasis Valley and the absence of significant interbasin flow between the PMOV groundwater basin and adjacent basins are shown regionally and locally. Regional constraints on the location of the contributing area boundary and on the absence of interbasin groundwater flow are shown by balancing groundwater discharges in the PMOV groundwater basin and adjacent basins against available water from precipitation. Internal consistency for the delineated contributing area is shown by matching measured water levels, groundwater discharges, and transmissivities with simulated results from a single-layer, steady-state, groundwater-flow model. An alternative basin boundary extending farther north than the final boundary was rejected based on a poor chloride mass balance and a large imbalance in the northern area between preferred and simulated recharge.

  18. Paleoenvironmental implications of lacustrine sedimentation patterns in the Temple Lake Valley, Wyoming

    SciTech Connect

    Zielinski, G.A.

    1987-01-01

    Lacustrine sediment cores were collected from three paternoster lakes in the Temple Lake valley, southern Wind River Range, Wyoming to model Holocene lacustrine sedimentation patterns and to evaluate controls on the sediment cascade system in this high-alpine valley. Coarse-grained sediments probably are deposited by turbidity flows and density underflows in Temple lake (3246 m) and by snow avalanching onto lake ice (dropstones.) in Miller Lake (3230 m). Such processes are minor in Rapid Lake (3134 m). Very poor sorting of fine-grained sediments suggests that fluvial and eolian components are recorded in sediment cores from each lake. Organic matter strongly influences chemical weathering in the Temple Lake valley. In addition, these 3 lakes are efficient sediment traps due to focusing of sediment to the deep upper end of each lake. Radiocarbon-dated sediment cores from lakes both inside and outside of the type Temple Lake moraine indicate that the deposit dates about 12,000 years B.P. Percentage organic detritus in these cores reach a maximum about 9500-8500 years B.P. and remain high from the early Holocene until 3300 years B.P., although slightly lower values occur 8500-7000 years B.P., probably not a period of major glacier activity. Similarly, valley-wall rock glaciers in lower Temple Lake valley probably were not active 5000 to 3000 years B.P. From 3300 years B.P. to almost the present, marked changes in most sediment parameters suggest an increase in physical weathering possibly associated with Neoglacial activity. Thus, the late-Pleistocene and Holocene glacial chronology of the Temple Lake valley includes a 12,000 years B.P. age for deposition of the type Temple lake moraine and a 3300 years B.P. age for the beginning of Neoglaciation.

  19. Transforming the "Valley of Death" into a "Valley of Opportunity"

    NASA Technical Reports Server (NTRS)

    Jedlovec, Gary J.; Merceret, Francis J.; O'Brien, T. P.; Roeder, William P.; Huddleston, Lisa L.; Bauman, William H., III

    2014-01-01

    Transitioning technology from research to operations (23 R2O) is difficult. The problem's importance is exemplified in the literature and in every failed attempt to do so. Although the R2O gap is often called the "valley of death", a recent a Space Weather editorial called it a "Valley of Opportunity". There are significant opportunities for space weather organizations to learn from the terrestrial experience. Dedicated R2O organizations like those of the various NOAA testbeds and collaborative "proving ground" projects take common approaches to improving terrestrial weather forecasting through the early transition of research capabilities into the operational environment. Here we present experience-proven principles for the establishment and operation of similar space weather organizations, public or private. These principles were developed and currently being demonstrated by NASA at the Applied Meteorology Unit (AMU) and the Short-term Prediction Research and Transition (SPoRT) Center. The AMU was established in 1991 jointly by NASA, the U.S. Air Force (USAF) and the National Weather Service (NWS) to provide tools and techniques for improving weather support to the Space Shuttle Program (Madura et al., 2011). The primary customers were the USAF 45th Weather Squadron (45 WS) and the NWS Spaceflight Meteorology Group (SMG who provided the weather observing and forecast support for Shuttle operations). SPoRT was established in 2002 to transition NASA satellite and remote-sensing technology to the NWS. The continuing success of these organizations suggests the common principles guiding them may be valuable for similar endeavors in the space weather arena.

  20. South: in the mild southern tradition

    SciTech Connect

    Price, T.L.

    1980-01-01

    Trends in the development of current and future energy resources in the southern states of the U.S. are reviewed. The south has the advantages of a mild climate and abundant sources of natural gas, coal, and hydro power, however, the supply and distribution of energy are primarily controlled by private and federal monopolies. The Tennessee Valley Authority (TVA) has a program for funding 100,000 solar domestic hot water systems plus low interest loans for wood heaters, zero interest conservation loans, and financing of passive solar homes. TVA will also construct a large passive solar complex. Other applications of solar technology discussed include installation in a brewery, apartment buildings, abandoned city housing, a duplex, an environmental center, a planned community, and a kiln company.

  1. Fracture density and spacing along Washita Valley fault, Arbuckle Mountains, Oklahoma

    SciTech Connect

    Ferebee, C.D.; Tapp, J.B. )

    1989-08-01

    The authors document fracture density and spacing associated with the Washita Valley fault, a major strike-slip fault. The Washita Valley fault strikes northwest-southeast with up to 80 mi of exposure in southern Oklahoma and may be an early bounding fault of the Southern Oklahoma aulacogen (Ardmore/Marietta basins). Horizontal displacement on the fault has been estimated to be up to 40 mi, with vertical displacement on the order of 10,000 ft. Samples collected from traverses across the Washita Valley fault have been analyzed. The traverses cross the fault at different stratigraphic levels from Proterozoic igneous basement, through the Cambrian-Ordovician Arbuckle Group, Ordovician Simpson and Viola Groups, to the Silurian-Devonian Hunton Group. Several types of fracture systems are documented that reflect mechanical stratigraphy, burial depth during deformation, and episodic movement on the fault. The fractures in the study area include open fracture systems, calcite-filled fractures, tension gashes, and fractures related to pressure solution. The samples were cut parallel to the strike of the fault, vertical-normal to the fault, and horizontal-normal to the fault. These cuts allow examination of the total fracture strain, characterization of the fractures, and statistical analysis of fracture density. From these data, fracture density is shown to decrease exponentially moving away from the primary fault zone. The increased understanding of fracture patterns and characteristics will assist future exploration and development programs involving carbonate reservoirs associated with strike-slip systems.

  2. Southern Ocean cephalopods.

    PubMed

    Collins, Martin A; Rodhouse, Paul G K

    2006-01-01

    The Southern Ocean cephalopod fauna is distinctive, with high levels of endemism in the squid and particularly in the octopodids. Loliginid squid, sepiids and sepiolids are absent from the Southern Ocean, and all the squid are oceanic pelagic species. The octopodids dominate the neritic cephalopod fauna, with high levels of diversity, probably associated with niche separation. In common with temperate cephalopods, Southern Ocean species appear to be semelparous, but growth rates are probably lower and longevity greater than temperate counterparts. Compared with equivalent temperate species, eggs are generally large and fecundity low, with putative long development times. Reproduction may be seasonal in the squid but is extended in the octopodids. Cephalopods play an important role in the ecology of the Southern Ocean, linking the abundant mesopelagic fish and crustaceans with higher predators such as albatross, seals and whales. To date Southern Ocean cephalopods have not been commercially exploited, but there is potential for exploitation of muscular species of the Family Ommastrephidae.

  3. Specters of Waste in India's "Silicon Valley": The Underside of Bangalore's Hi-Tech Economy

    ERIC Educational Resources Information Center

    Narayanareddy, Rajyashree

    2011-01-01

    The southern Indian city of Bangalore is extolled as India's "Silicon Valley," emerging over the past decade as a premier site for capital flows into India's Information Technology (IT) sector. In the dominant narrative of globalization Bangalore is lauded as an aspiring "global city" that attracts sizeable quantities…

  4. Holocene geologic slip rate for the Banning strand of the southern San Andreas Fault, southern California

    USGS Publications Warehouse

    Gold, Peter O.; Behr, Whitney M.; Rood, Dylan; Sharp, Warren D.; Rockwell, Thomas; Kendrick, Katherine J.; Salin, Aaron

    2015-01-01

    Northwest directed slip from the southern San Andreas Fault is transferred to the Mission Creek, Banning, and Garnet Hill fault strands in the northwestern Coachella Valley. How slip is partitioned between these three faults is critical to southern California seismic hazard estimates but is poorly understood. In this paper, we report the first slip rate measured for the Banning fault strand. We constrain the depositional age of an alluvial fan offset 25 ± 5 m from its source by the Banning strand to between 5.1 ± 0.4 ka (95% confidence interval (CI)) and 6.4 + 3.7/−2.1 ka (95% CI) using U-series dating of pedogenic carbonate clast coatings and 10Be cosmogenic nuclide exposure dating of surface clasts. We calculate a Holocene geologic slip rate for the Banning strand of 3.9 + 2.3/−1.6 mm/yr (median, 95% CI) to 4.9 + 1.0/−0.9 mm/yr (median, 95% CI). This rate represents only 25–35% of the total slip accommodated by this section of the southern San Andreas Fault, suggesting a model in which slip is less concentrated on the Banning strand than previously thought. In rejecting the possibility that the Banning strand is the dominant structure, our results highlight an even greater need for slip rate and paleoseismic measurements along faults in the northwestern Coachella Valley in order to test the validity of current earthquake hazard models. In addition, our comparison of ages measured with U-series and 10Be exposure dating demonstrates the importance of using multiple geochronometers when estimating the depositional age of alluvial landforms.

  5. Wave propagation and site response in the Santa Clara Valley

    USGS Publications Warehouse

    Fletcher, Joe B.; Boatwright, J.; Lindh, A.G.

    2003-01-01

    Forty-two portable digital instruments were deployed across the Santa Clara Valley from June until early November 1998; this array recorded 14 small and moderate local events and 7 large teleseismic events. We analyze the ground motion from these events to determine station delays and relative site amplification within the Valley. P waves from an event at the southern edge of the valley are early (??t > -0.35 sec) at stations over an axial ridge in the basement interface in the middle of the valley, but late (??t < 0.20 sec) for stations over the Cupertino and Evergreen basins to either side. The S-wave delays are approximately twice as large. Teleseismic P-waves from an M = 7.0 event beneath the Bonin Islands show a similar pattern in travel-time delays. The P waves are amplified by factors of 1.5-3 for frequencies below 2 Hz at stations within either basin, compared with stations on the axial ridge. The P-wave coda appear enhanced at 2-3 sec, but coda Q estimates at frequencies from 0.2 to 1.1 Hz are not markedly different at stations over the basin compared with stations on the ridge with the possible exceptions of consistently high values over the northern end of the Evergreen Basin. We invert the S-wave spectra for site-specific attenuation and amplification from the 14 local events by assuming a common source spectra for each event, 1/r geometrical spreading, and constraining the inversion using the 30-m velocity profile at four stations in the array. The largest amplifications occurred in the 1- to 6-Hz band at stations near the northwest edge of the Evergreen basin. While the highest amplifications occur at stations with the lowest S-wave velocities, the scatter obscures the correlation between velocity and amplification. The stations in the basins are characterized by higher attenuation than the stations on the basement ridge.

  6. Southern Identity in "Southern Living" Magazine

    ERIC Educational Resources Information Center

    Lauder, Tracy

    2012-01-01

    A fantasy-theme analysis of the editors' letters in "Southern Living" magazine shows an editorial vision of valuing the past and showcasing unique regional qualities. In addition, a content analysis of the visual representation of race in the magazine's formative years and recent past validates that inhabitants of the region were portrayed…

  7. Structure and Velocities of the Northeastern Santa Cruz Mountains and the Western Santa Clara Valley, California, from the SCSI-LR Seismic Survey

    USGS Publications Warehouse

    Catchings, R.D.; Goldman, M.R.; Gandhok, G.

    2006-01-01

    Introduction: The Santa Clara Valley is located in the southern San Francisco Bay area of California and generally includes the area south of the San Francisco Bay between the Santa Cruz Mountains on the southwest and the Diablo Ranges on the northeast. The area has a population of approximately 1.7 million including the city of San Jose, numerous smaller cities, and much of the high-technology manufacturing and research area commonly referred to as the Silicon Valley. Major active strands of the San Andreas Fault system bound the Santa Clara Valley, including the San Andreas fault to the southwest and the Hayward and Calaveras faults to the northeast; related faults likely underlie the alluvium of the valley. This report focuses on subsurface structures of the western Santa Clara Valley and the northeastern Santa Cruz Mountains and their potential effects on earthquake hazards and ground-water resource management in the area. Earthquake hazards and ground-water resources in the Santa Clara Valley are important considerations to California and the Nation because of the valley's preeminence as a major technical and industrial center, proximity to major earthquakes faults, and large population. To assess the earthquake hazards of the Santa Clara Valley better, the U.S. Geological Survey (USGS) has undertaken a program to evaluate potential earthquake sources and potential effects of strong ground shaking within the valley. As part of that program, and to better assess water resources of the valley, the USGS and the Santa Clara Valley Water District (SCVWD) began conducting collaborative studies to characterize the faults, stratigraphy, and structures beneath the alluvial cover of the Santa Clara Valley in the year 2000. Such geologic features are important to both agencies because they directly influence the availability and management of groundwater resources in the valley, and they affect the severity and distribution of strong shaking from local or regional

  8. Climate-disease connections: Rift Valley Fever in Kenya

    NASA Technical Reports Server (NTRS)

    Anyamba, A.; Linthicum, K. J.; Tucker, C. J.

    2001-01-01

    All known Rift Valley fever(RVF) outbreaks in Kenya from 1950 to 1998 followed periods of abnormally high rainfall. On an interannual scale, periods of above normal rainfall in East Africa are associated with the warm phase of the El Nino/Southern Oscillation (ENSO) phenomenon. Anomalous rainfall floods mosquito-breeding habitats called dambos, which contain transovarially infected mosquito eggs. The eggs hatch Aedes mosquitoes that transmit the RVF virus preferentially to livestock and to humans as well. Analysis of historical data on RVF outbreaks and indicators of ENSO (including Pacific and Indian Ocean sea surface temperatures and the Southern Oscillation Index) indicates that more than three quarters of the RVF outbreaks have occurred during warm ENSO event periods. Mapping of ecological conditions using satellite normalized difference vegetation index (NDVI) data show that areas where outbreaks have occurred during the satellite recording period (1981-1998) show anomalous positive departures in vegetation greenness, an indicator of above-normal precipitation. This is particularly observed in arid areas of East Africa, which are predominantly impacted by this disease. These results indicate a close association between interannual climate variability and RVF outbreaks in Kenya.

  9. Valley of the Brahmaputra, India

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this true-color MODIS image from October 23, 2001, the semi-arid Tibetan Plateau (upper left) meets up with the Himalayas to the south. From the heights of the Himalayas, snow-covered on their northern flanks, and lush with vegetation to the south, numerous rivers, brown with churned up sediment, flow into the valley of the Brahmaputra River in Assam, India. The Brahmaputra turns southward at the border of Bangladesh and is soon joined by the Ganges River, flowing in from image left. The mighty river splits into numerous channels as it runs out toward the Bay of Bengal, giving the region the name 'Mouths of the Ganges.' Vast amounts of sediment are being emptied into the Bay by the river, and greenish blue swirls could be a mixture of sediment and phytoplankton. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  10. Timing of Mississippi Valley-type mineralization: Relation to Appalachian orogenic events

    SciTech Connect

    Kesler, S.E.; van der Pluijm, B.A. )

    1990-11-01

    Although Mississippi Valley-type deposits in Lower Ordovician carbonate rocks of the Appalachian orogen are commonly interpreted to have been precipitated by basinal brines, the timing of brine migration remains poorly known. Late Paleozoic K-Ar isotopic ages on authigenic K-feldspar, which is widespread in Appalachian carbonate rocks, as well as evidence of paleomagnetic overprints of similar age, have focused attention on the possibility that these Mississippi Valley-type deposits formed as a result of late Paleozoic deformation. Geologic and geochemical similarities among most of these deposits, from Georgia to Newfoundland, including unusually high sphalerite/galena ratios, isotopically heavy sulfur, and relatively nonradiogenic lead, suggest that they are coeval. Sphalerite sand that parallels host-rock layering in many of the deposits indicates that mineralization occurred before regional deformation. Although the late Paleozoic age of deformation in the southern Appalachians provides little constraint on the age of Mississippi Valley-type mineralization, deformation of these deposits in the Newfoundland Appalachians is early to middle Paleozoic in age. Thus, if Ordovician-hosted, Appalachian Mississippi Valley-type deposits are coeval, they must have formed by middle Paleozoic time and cannot be the product of a late Paleozoic fluid-expulsion event. This hypothesis has important implications for basin evolution, fluid events, and remagnetization in the Appalachians.

  11. Catastrophic flooding origin of shelf valley systems in the English Channel.

    PubMed

    Gupta, Sanjeev; Collier, Jenny S; Palmer-Felgate, Andy; Potter, Graeme

    2007-07-19

    Megaflood events involving sudden discharges of exceptionally large volumes of water are rare, but can significantly affect landscape evolution, continental-scale drainage patterns and climate change. It has been proposed that a significant flood event eroded a network of large ancient valleys on the floor of the English Channel-the narrow seaway between England and France. This hypothesis has remained untested through lack of direct evidence, and alternative non-catastrophist ideas have been entertained for valley formation. Here we analyse a new regional bathymetric map of part of the English Channel derived from high-resolution sonar data, which shows the morphology of the valley in unprecedented detail. We observe a large bedrock-floored valley that contains a distinct assemblage of landforms, including streamlined islands and longitudinal erosional grooves, which are indicative of large-scale subaerial erosion by high-magnitude water discharges. Our observations support the megaflood model, in which breaching of a rock dam at the Dover Strait instigated catastrophic drainage of a large pro-glacial lake in the southern North Sea basin. We suggest that megaflooding provides an explanation for the permanent isolation of Britain from mainland Europe during interglacial high-sea-level stands, and consequently for patterns of early human colonisation of Britain together with the large-scale reorganization of palaeodrainage in northwest Europe. PMID:17637667

  12. Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica

    USGS Publications Warehouse

    Esposito, R.M.M.; Spaulding, S.A.; McKnight, Diane M.; Van De Vijver, B.; Kopalova, K.; Lubinski, D.; Hall, B.; Whittaker, T.

    2008-01-01

    Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species (Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6-10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent. ?? 2008 NRC.

  13. Catastrophic flooding origin of shelf valley systems in the English Channel.

    PubMed

    Gupta, Sanjeev; Collier, Jenny S; Palmer-Felgate, Andy; Potter, Graeme

    2007-07-19

    Megaflood events involving sudden discharges of exceptionally large volumes of water are rare, but can significantly affect landscape evolution, continental-scale drainage patterns and climate change. It has been proposed that a significant flood event eroded a network of large ancient valleys on the floor of the English Channel-the narrow seaway between England and France. This hypothesis has remained untested through lack of direct evidence, and alternative non-catastrophist ideas have been entertained for valley formation. Here we analyse a new regional bathymetric map of part of the English Channel derived from high-resolution sonar data, which shows the morphology of the valley in unprecedented detail. We observe a large bedrock-floored valley that contains a distinct assemblage of landforms, including streamlined islands and longitudinal erosional grooves, which are indicative of large-scale subaerial erosion by high-magnitude water discharges. Our observations support the megaflood model, in which breaching of a rock dam at the Dover Strait instigated catastrophic drainage of a large pro-glacial lake in the southern North Sea basin. We suggest that megaflooding provides an explanation for the permanent isolation of Britain from mainland Europe during interglacial high-sea-level stands, and consequently for patterns of early human colonisation of Britain together with the large-scale reorganization of palaeodrainage in northwest Europe.

  14. Water-resources of the Antelope Valley-East Kern Water Agency area, California

    USGS Publications Warehouse

    Bloyd, R.M.

    1967-01-01

    The Antelope Valley-East Kern Water Agency (AVEK) area, most of which is within the Mojave Desert region of southern California, lacks adequate water resources to sustain the existing rate of ground-water pumpage for irrigation, industrial, and domestic use. However, by 1972 the California Aqueduct, a part of the California Water Plan, will be completed and will begin to convey water from northern California into the area. The chief economic pursuits in the area are irrigated agriculture and poultry production. At present, the major industries are related to national defense and mining. In the future, industry will increase and probably become the major economic activity. The Mojave Desert region, part of which lies within the AVEK area, is characterized by fault-block mountains and fault-block basins. The Tehachapi and San Gabriel Mountains are the major bordering fault blocks. The adjacent lowland areas of Antelope and Fremont Valleys have been depressed by movements along major faults. There are two major ground-water basins in the AVEK area: Antelope Valley and Fremont Valley basins. Each large basin is divided by faults or bodies of consolidated rock into several groundwater subunits.

  15. Long Valley Exploratory Well - Summary

    SciTech Connect

    Tennyson, George P. Jr.

    1992-03-24

    As was stated by the first presenter, the Long Valley Exploratory Well represents a vital linking of geothermal theory, technology and applications. The five presenters take us through that linking to the extent the current progress at the well makes that possible. The site is, of course, a geothermally rich resource, a ''recently active'' caldera. In many ways, the site has a wealth of data preceding the present work. It is a site which has excited the interest of the geothermal community for a long time. As is often the case in geothermal work, the prior data has raised as many questions as were answered. It is on this basis that the further exploration of a probable high temperature resource is being explored to great depths. The first presentation represents the cooperation and coordination maintained between similar elements of the Basic Energy Sciences programs and those in the Geothermal programs of DOE's Conservation and Renewable Energy activities. Similarly, the work exemplifies the close coordination of the DOE work with the U. S. Geological Survey, the National Science Foundation, and the U. S. Continental Scientific Drilling Program. The first presentation also represents the theoretical and modeling portion of the session. Appropriate to geothermal technology, the central programmatic theme is geophysical and geochemical aspects of fluid flow and interaction in porous and fractured rocks. It was interesting to note that even the theoretical work and modeling addressed the applicability to earth-based energy resources, and as well their utilization in a manner such as to assure environmental acceptability. Topics addressed included: (1) fundamental properties and interactions of rocks, mineral, and fluids; (2) transport and flow of fluids in rocks; and (3) structure of geologic units. The session continued with the description of the Phase II operations at the Long Valley Exploratory Well. The drilling operations were described as relatively trouble

  16. Valley blockade and multielectron spin-valley Kondo effect in silicon

    NASA Astrophysics Data System (ADS)

    Crippa, A.; Tagliaferri, M. L. V.; Rotta, D.; De Michielis, M.; Mazzeo, G.; Fanciulli, M.; Wacquez, R.; Vinet, M.; Prati, E.

    2015-07-01

    We report on the valley blockade and the multielectron Kondo effect generated by an impurity atom in a silicon nanofield effect device. According to the spin-valley nature of tunneling processes, and consistently with those allowed by the valley blockade regime, the manifestation of Kondo effect at occupation N =1 ,2 ,3 has the periodicity 4 of the electron filling sequence typical of silicon. The spin-valley Kondo effect emerges under different kinds of screening depending on the electron filling. By exploiting the valley blockade regime, valley index conservation in the Kondo SU(4) is deduced with no need of an external magnetic field. Microwave irradiation suppresses the Kondo effect at occupancies up to three electrons.

  17. Interpretive geologic cross sections for the Death Valley regional flow system and surrounding areas, Nevada and California

    SciTech Connect

    D.S. Sweetkind; R.P. Dickerson; R.J. Blakely; P.D. Denning

    2001-11-09

    This report presents a network of 28 geologic cross sections that portray subsurface geologic relations within the Death Valley regional ground-water system, a ground-water basin that encompasses a 3 degree x 3 degree area (approximately 70,000 square kilometers) in southern Nevada and eastern California. The cross sections transect that part of the southern Great Basin that includes Death Valley, the Nevada Test Site, and the potential high-level nuclear waste underground repository at Yucca Mountain. The specific geometric relationships portrayed on the cross sections are discussed in the context of four general sub-regions that have stratigraphic similarities and general consistency of structural style: (1) the Nevada Test Site vicinity; (2) the Spring Mountains, Pahrump Valley and Amargosa Desert region; (3) the Death Valley region; and (4) the area east of the Nevada Test Site. The subsurface geologic interpretations portrayed on the cross sections are based on an integration of existing geologic maps, measured stratigraphic sections, published cross sections, well data, and geophysical data and interpretations. The estimated top of pre-Cenozoic rocks in the cross sections is based on inversion of gravity data, but the deeper parts of the sections are based on geologic conceptual models and are more speculative.

  18. Quaternary tectonics and basin history of Pahrump and Stewart Valleys, Nevada and California. [Yucca Mountain Project

    SciTech Connect

    Hoffard, J.L. )

    1991-05-01

    The Pahrump fault system is an active fault system located in Pahrump and Stewart Valleys, Nevada and California, in the southern part of the Basin and Range Province. This system is 50 km long by 30 km wide and is comprised of three fault zones: the right-lateral East Nopah fault zone, the right-oblique Pahrump Valley fault zone, and the normal West Spring Mountains fault zone. All three zones have geomorphic evidence for late Quaternary activity. Analysis of active fault patterns and seismic reflection lines suggests that the Pahrump basin has had a two-stage genesis, an early history associated with a period of low angle detachment faulting probably active 10-15 Ma, and a more recent history related to the present dextral shear system, probably active post-4 Ma.

  19. Quaternary tectonics and basin history of Pahrump and Stewart Valleys, Nevada and California

    SciTech Connect

    Hoffard, J.L.

    1991-05-01

    The Pahrump fault system is an active fault system located in Pahrump and Stewart Valleys, Nevada and California, in the southern part of the Basin and Range Province. This system is 50 km long by 30 km wide and is comprised of three fault zones: the right-lateral East Nopah fault zone, the right-oblique Pahrump Valley fault zone, and the normal West Spring Mountains fault zone. All three zones have geomorphic evidence for late Quaternary activity. Analysis of active fault patterns and seismic reflection lines suggests that the Pahrump basin has had a two-stage genesis, an early history associated with a period of low angle detachment faulting probably active 10-15 Ma, and a more recent history related to the present dextral shear system, probably active post-4 Ma.

  20. High-resolution area-wide sea-floor mapping: The paleo Elbe valley (S North Sea) revisited

    NASA Astrophysics Data System (ADS)

    Papenmeier, Svenja; Hass, H. Christian

    2014-05-01

    The North Sea Basin is shaped by multiple glacial advances and retreats that left complex sequences of glacio-fluvial and sub-glacial deposits, cut by sub-glacial tunnel valleys. Today, the submerged valley of the Elbe forms one of the most prominent structures of the southern North Sea. Flanked by huge moraine deposits of older glacials, the valley developed to its present form during the Weichselian sea-level lowstand (-130 m below present). Melt waters that discharged in north-westerly directions along the Scandinavian Ice Sheet fed the paleo Elbe at that time. During the Holocene the valley drowned in the rising sea. Here we present an area-wide high-resolution map of the seafloor and high-resolution shallow seismic data covering 1,600 km2 of the paleo Elbe valley (PEV) including its eastern levee. The data allow to shed new light on the PEV development including the historical process of sedimentary infill with the successive Holocene sea level rise in detail. Shallow seismic data with transect distances of 400 m and several cross sections allow 3-D visualization. The eastern flank of the valley is characterized by a relatively steep slope with one or more terraces. At its levee a significant sediment change is present on the modern sea floor, representing moraine and marine deposits. High resolution sidescan sonar data of this area show a much higher heterogeneity and complexity in sediment and habitat distribution as assumed before. Holocene marine sediments form a patchy and thin drape east of the valley floor. The western slip-off slope of the valley slope is much smoother than the eastern undercut slope. As yet, significant sedimentological changes at the present seafloor are not known for the western side of the PEV. Shallow seismic data show the base of the PEV. There are conspicuous internal seismic reflectors above the base, inclined in northeastern direction. They indicate a sedimentary infill of the valley from the southwest when the southern part

  1. 76 FR 22746 - Conecuh Valley Railway, LLC-Acquisition and Operation Exemption-Conecuh Valley Railroad Co., Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Surface Transportation Board Conecuh Valley Railway, LLC--Acquisition and Operation Exemption--Conecuh Valley Railroad Co., Inc. Conecuh Valley Railway, LLC (CVR), a noncarrier, has filed a verified notice of exemption under 49 CFR 1150.31 to acquire from Conecuh Valley Railroad Co., Inc. (COEH), and to...

  2. Valley and electric photocurrents in 2D silicon and graphene

    SciTech Connect

    Tarasenko, S. A.; Ivchenko, E. L.; Olbrich, P.; Ganichev, S. D.

    2013-12-04

    We show that the optical excitation of multi-valley systems leads to valley currents which depend on the light polarization. The net electric current, determined by the vector sum of single-valley contributions, vanishes for some peculiar distributions of carriers in the valley and momentum spaces forming a pure valley current. We report on the study of this phenomenon, both experimental and theoretical, for graphene and 2D electron channels on the silicon surface.

  3. 27 CFR 9.150 - Cucamonga Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., photorevised 1981; (10) Corona North, Calif., 1967, photorevised 1981. (c) Boundary. The Cucamonga Valley... it ends at Limonite Avenue in the northeast corner of the Corona North, Calif., U.S.G.S. map;...

  4. Deer Lodge Valley investigations, western Montana

    SciTech Connect

    Wideman, C.J.; Sonderegger, J.; Crase, E.; Peterson, J.; Ruscetta, C.A.

    1982-07-01

    A review of the geothermal investigations conducted in the Deer Lodge Valley of Western Montana is briefly presented. Maps of the generalized geology and Bouguer gravity and graphs of selected geothermal gradients and resistivity sounding profiles are presented. (MJF)

  5. Small Martian valleys - Pristine and degraded morphology

    NASA Astrophysics Data System (ADS)

    Baker, V. R.; Partridge, J. B.

    1986-03-01

    This study is concerned with a more detailed investigation of the small valley networks on Mars. The dual nature of many valley systems is pointed out, taking into account a relatively fresh-appearing network portion versus an apparent larger, less distinct network system. These separate network characteristics are referred to as pristine and degraded. The valley networks included in this study are all located in the equatorial zone of heavily cratered uplands, between latitudes 30 deg N and 40 deg S. Aspects of network morphology are examined, taking into account drainage density, network dissection ratio, and valley length parameters. Age relationships are also discussed, giving attention to crater age, counting problems, a conservative method, and a crater-fraction method.

  6. Airborne Dust Models in Valley Fever Research

    NASA Astrophysics Data System (ADS)

    Sprigg, W. A.; Galgiani, J. N.; Vujadinovic, M.; Pejanovic, G.; Vukovic, A. J.; Prasad, A. K.; Djurdjevic, V.; Nickovic, S.

    2011-12-01

    Dust storms (haboobs) struck Phoenix, Arizona, in 2011 on July 5th and again on July 18th. One potential consequence: an estimated 3,600 new cases of Valley Fever in Maricopa County from the first storm alone. The fungi, Coccidioides immitis, the cause of the respiratory infection, Valley Fever, lives in the dry desert soils of the American southwest and southward through Mexico, Central America and South America. The fungi become part of the dust storm and, a few weeks after inhalation, symptoms of Valley Fever may appear, including pneumonia-like illness, rashes, and severe fatigue. Some fatalities occur. Our airborne dust forecast system predicted the timing and extent of the storm, as it has done with other, often different, dust events. Atmosphere/land surface models can be part of public health services to reduce risk of Valley Fever and exacerbation of other respiratory and cardiovascular illness.

  7. Mississippi Valley State University educational outreach

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Pat Gaspard, a visitor relations specialist with NASA's StenniSphere visitor center, speaks to Mississippi Valley State University students. Gaspard spoke July 15 during Stennis Space Center's three-day educational outreach program at the college.

  8. 27 CFR 9.150 - Cucamonga Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., photorevised 1981; (10) Corona North, Calif., 1967, photorevised 1981. (c) Boundary. The Cucamonga Valley... it ends at Limonite Avenue in the northeast corner of the Corona North, Calif., U.S.G.S. map;...

  9. 27 CFR 9.150 - Cucamonga Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., photorevised 1981; (10) Corona North, Calif., 1967, photorevised 1981. (c) Boundary. The Cucamonga Valley... it ends at Limonite Avenue in the northeast corner of the Corona North, Calif., U.S.G.S. map;...

  10. 27 CFR 9.150 - Cucamonga Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., photorevised 1981; (10) Corona North, Calif., 1967, photorevised 1981. (c) Boundary. The Cucamonga Valley... it ends at Limonite Avenue in the northeast corner of the Corona North, Calif., U.S.G.S. map;...

  11. 27 CFR 9.150 - Cucamonga Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., photorevised 1981; (10) Corona North, Calif., 1967, photorevised 1981. (c) Boundary. The Cucamonga Valley... it ends at Limonite Avenue in the northeast corner of the Corona North, Calif., U.S.G.S. map;...

  12. Goldstone Apple Valley Radio Telescope Project.

    ERIC Educational Resources Information Center

    Ibe, Mary; MacLaren, Dave

    2003-01-01

    Describes the Goldstone Apple Valley Radio Telescope (GAVRT) project as a way of teaching astronomy concepts to middle school students. The project provides students opportunities to work with professional scientists. (SOE)

  13. Documentation of the Santa Clara Valley regional ground-water/surface-water flow model, Santa Clara Valley, California

    USGS Publications Warehouse

    Hanson, R.T.; Li, Zhen; Faunt, C.C.

    2004-01-01

    The Santa Clara Valley is a long, narrow trough extending about 35 miles southeast from the southern end of San Francisco Bay where the regional alluvial-aquifer system has been a major source of water. Intensive agricultural and urban development throughout the 20th century and related ground-water development resulted in ground-water-level declines of more than 200 feet and land subsidence of as much as 12.7 feet between the early 1900s and the mid-1960s. Since the 1960s, Santa Clara Valley Water District has imported surface water to meet growing demands and reduce dependence on ground-water supplies. This importation of water has resulted in a sustained recovery of the ground-water flow system. To help support effective management of the ground-water resources, a regional ground-water/surface-water flow model was developed. This model simulates the flow of ground water and surface water, changes in ground-water storage, and related effects such as land subsidence. A numerical ground-water/surface-water flow model of the Santa Clara Valley subbasin of the Santa Clara Valley was developed as part of a cooperative investigation with the Santa Clara Valley Water District. The model better defines the geohydrologic framework of the regional flow system and better delineates the supply and demand components that affect the inflows to and outflows from the regional ground-water flow system. Development of the model includes revisions to the previous ground-water flow model that upgraded the temporal and spatial discretization, added source-specific inflows and outflows, simulated additional flow features such as land subsidence and multi-aquifer wellbore flow, and extended the period of simulation through September 1999. The transient-state model was calibrated to historical surface-water and ground-water data for the period 197099 and to historical subsidence for the period 198399. The regional ground-water flow system consists of multiple aquifers that are grouped

  14. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    USGS Publications Warehouse

    Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  15. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    USGS Publications Warehouse

    Scanlon, Bridget R.; Faunt, Claudia; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  16. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley.

    PubMed

    Scanlon, Bridget R; Faunt, Claudia C; Longuevergne, Laurent; Reedy, Robert C; Alley, William M; McGuire, Virginia L; McMahon, Peter B

    2012-06-12

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km(3) of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km(3), occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km(3) shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  17. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    PubMed Central

    Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley. PMID:22645352

  18. Southern hemisphere observations

    NASA Astrophysics Data System (ADS)

    Orchiston, Wayne

    Because of insurmountable problems associated with absolute dating, the non-literate cultures of the Southern Hemisphere can contribute little to Applied Historical Astronomy, although Maori traditions document a possible supernova dating to the period 1000-1770 AD. In contrast, the abundant nineteenth century solar, planetary, cometary and stellar observational data provided by Southern Hemisphere professional and amateur observatories can serve as an invaluable mine of information for present-day astronomers seeking to incorporate historical data in their investigations.

  19. An evaluation of Skylab (EREP) remote sensing techniques applied to investigation of crustal structure. [Death Valley and Greenwater Valley (CA)

    NASA Technical Reports Server (NTRS)

    Bechtold, I. C. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. A study of Greenwater Valley indicates that the valley is bounded on the north and east by faults, on the south by a basement high, and on the west by the dip slope of the black mountains, movement of ground water from the valley is thus Movement of ground water from the valley is thus restricted, indicating the valley is a potential water reservoir.

  20. Types of river valleys as a criterion for estimation of the territory geodiversity

    NASA Astrophysics Data System (ADS)

    Opekunova, Marina; Vyrkin, Vladimir

    2015-04-01

    The Oka plateau occupies an intermediate position between large morphostructures of Southern Siberia. It is a unique object, where the features of relief development of the contiguous areas were reflected. The structure of the plateau also includes the Ilchir-Kitoi depression, located in the southeast, and the Oka depression, which lies in the north-west. The river network is characterized by deeply incised valleys, the relief of which bears traces of glacial activity, manifestations of Cenozoic volcanism, and active neotectonic movements. These factors also determine a wide variability in distribution of the types of river valleys: from the valleys with the hilly-moraine topography to the broad-floodplain sections of valleys with an instrativ floodplain-terrace complex and incised type of channel when the river crosses basalt fields. Thus, the antecedent Oka river valley of ancient formation was actively affected by volcanism and glaciation in Late Cenozoic. Lava flows enabled the formation of the incised and adapted types of channels within the south-western part of the Oka depression. Large areas of distribution of basalts on the left-bank part of the Oka river basin, occupying mainly the watershed positions, contributed to the formation of a certain type of longitudinal profiles of channels, characterized by a shallow form in the upper reaches (in the field of basalts development) and by a steep form in the middle and lower sections of the valleys. The distribution of fluvioglacial landforms and moraine ridges descending into the Oka valley along the tributaries (Sentsa, Gargan and others), and the presence of facies transitions from fluvioglacial and glacial to alluvial deposits determine the specific type of river valleys, developed under the conditions of the glacial relief formation. Due to the uplift of the Kropotkin range, the river erosion within the plateau is relatively slowed down in comparison with the surrounding mountains, which is reflected in the

  1. Lateral spread hazard mapping of the northern Salt Lake Valley, Utah, for a M7.0 scenario earthquake

    USGS Publications Warehouse

    Olsen, M.J.; Bartlett, S.F.; Solomon, B.J.

    2007-01-01

    This paper describes the methodology used to develop a lateral spread-displacement hazard map for northern Salt Lake Valley, Utah, using a scenario M7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault. The mapping effort is supported by a substantial amount of geotechnical, geologic, and topographic data compiled for the Salt Lake Valley, Utah. ArcGIS?? routines created for the mapping project then input this information to perform site-specific lateral spread analyses using methods developed by Bartlett and Youd (1992) and Youd et al. (2002) at individual borehole locations. The distributions of predicted lateral spread displacements from the boreholes located spatially within a geologic unit were subsequently used to map the hazard for that particular unit. The mapped displacement zones consist of low hazard (0-0.1 m), moderate hazard (0.1-0.3 m), high hazard (0.3-1.0 m), and very high hazard (> 1.0 m). As expected, the produced map shows the highest hazard in the alluvial deposits at the center of the valley and in sandy deposits close to the fault. This mapping effort is currently being applied to the southern part of the Salt Lake Valley, Utah, and probabilistic maps are being developed for the entire valley. ?? 2007, Earthquake Engineering Research Institute.

  2. Environmental changes bridge evolutionary valleys

    PubMed Central

    Steinberg, Barrett; Ostermeier, Marc

    2016-01-01

    In the basic fitness landscape metaphor for molecular evolution, evolutionary pathways are presumed to follow uphill steps of increasing fitness. How evolution can cross fitness valleys is an open question. One possibility is that environmental changes alter the fitness landscape such that low-fitness sequences reside on a hill in alternate environments. We experimentally test this hypothesis on the antibiotic resistance gene TEM-15 β-lactamase by comparing four evolutionary strategies shaped by environmental changes. The strategy that included initial steps of selecting for low antibiotic resistance (negative selection) produced superior alleles compared with the other three strategies. We comprehensively examined possible evolutionary pathways leading to one such high-fitness allele and found that an initially deleterious mutation is key to the allele’s evolutionary history. This mutation is an initial gateway to an otherwise relatively inaccessible area of sequence space and participates in higher-order, positive epistasis with a number of neutral to slightly beneficial mutations. The ability of negative selection and environmental changes to provide access to novel fitness peaks has important implications for natural evolutionary mechanisms and applied directed evolution. PMID:26844293

  3. Hydrogeology of the Tully Trough in Southern Onondaga County and Northern Cortland County, New York

    USGS Publications Warehouse

    Kappel, William M.; Miller, Todd S.

    2003-01-01

    A trough valley near Tully, N.Y. was formed by the same glacial processes that formed the Finger Lake valleys to the west. Glacial ice eroded a preglacial bedrock divide along the northern rim of the Allegheny Plateau and deepened a preglacial valley to form a trough valley. Subsequent meltwater issuing from the ice transported and deposited large amounts of sediment which partly filled the trough. The Tully trough contains three distinct segments?the West Branch valley of the southward-flowing Tioughnioga River in the south, the Valley Heads Moraine near Tully, and the Tully valley of the northward-flowing Onondaga Creek in the north. The West Branch valley segment south of the moraine contains a two-aquifer system?a surficial unconfined sand and gravel aquifer and a confined basal sand and gravel aquifer that rests on bedrock, separated by a thick, fine-grained glaciolacustrine fine sand, silt, and clay unit. Water quality in the surficial aquifer is generally good, although it is typically hard. Water in the basal, confined aquifer is more mineralized and yields less water to wells than the surficial aquifer. The Valley Heads Moraine near Tully consists of layers of sand and gravel, fine sand, silt, clay, and till. The land surface contains many kettle-hole lakes, ponds, wetlands, and dry depressions. The moraine contains several aquifers, some of which are discontinuous. Water quality in the shallow aquifers is generally good, although hard. Water quality in the deep aquifer is generally good, although slightly mineralized by water discharging upward from shale. The Tully valley segment north of the moraine has a confined basal sand-and-gravel aquifer that is overlain by a thick layer of lacustrine silt and clay in the southern part of the valley and becomes interlayered with sand and some fine gravel in the northern part. Most homeowners obtain their water supply from streams or springs along the valley walls or from wells. Water from wells completed in coarse

  4. Measurements of Refractory Black Carbon (rBC) Aerosols in the McMurdo Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Khan, A. L.; McMeeking, G. R.; Lyons, W. B.; Schwarz, J. P.; Welch, K. A.; McKnight, D. M.

    2015-12-01

    Measurements of light absorbing particles in the boundary layer of the high southern latitudes are scarce. During the 2013-2014 austral summer field season refractory black carbon (rBC) aerosols were quantified by a single particle soot photometer (SP2) in the McMurdo Dry Valleys, Antarctica. The dark rBC particles absorb more radiation thereby increasing atmospheric heating, as well as reducing surface albedo and enhancing hydrologic melt when deposited on highly reflective surfaces such as snow and ice. Quantifying both local and long-range atmospheric transport of rBC to this region of a remote continent mostly covered by ice and snow would be useful in understanding meltwater generation as climate changes. Although the Dry Valleys are the largest ice-free region of Antarctica, they contain many alpine glaciers, some of which are fed from the East Antarctic Ice Sheet (EAIS). Continuous rBC measurements were collected at Lake Hoare Camp in the Taylor Valley for two months, along with shorter periods at more remote locations within the Dry Valleys. Conditions at the Lake Hoare Camp were dominated by up-valley winds from McMurdo Sound, however, winds also brought air down-valley from the EAIS polar plateau. Here we investigated periods dominated by both up and down-valley winds to explore differences in rBC concentrations, size distributions, and scattering properties. The average background rBC mass concentration was 1ng/m3, though concentrations as high as 50 ng/m3 were observed at times, likely due to local sources.

  5. Drought, Land-Use Change, and Water Availability in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Faunt, C. C.; Sneed, M.; Traum, J.

    2015-12-01

    The Central Valley is a broad alluvial-filled structural trough that covers about 52,000 square kilometers and is one of the most productive agricultural regions in the world. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture developed a reliance on groundwater for irrigation. During recent drought periods (2007-09 and 2012-present), groundwater pumping has increased due to a combination of factors including drought and land-use changes. In response, groundwater levels have declined to levels approaching or below historical low levels. In the San Joaquin Valley, the southern two thirds of the Central Valley, the extensive groundwater pumpage has caused aquifer system compaction, resulting in land subsidence and permanent loss of groundwater storage capacity. The magnitude and rate of subsidence varies based on geologic materials, consolidation history, and historical water levels. Spatially-variable subsidence has changed the land-surface slope, causing operational, maintenance, and construction-design problems for surface-water infrastructure. It is important for water agencies to plan for the effects of continued water-level declines, storage losses, and/or land subsidence. To combat these effects, excess surface water, when available, is artificially recharged. As surface-water availability, land use, and artificial recharge continue to vary, long-term groundwater-level and land-subsidence monitoring and modelling are critical to understanding the dynamics of the aquifer system. Modeling tools, such as the Central Valley Hydrologic Model, can be used in the analysis and evaluation of management strategies to mitigate adverse impacts due to subsidence, while also optimizing water availability. These analyses will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  6. Upper Neogene stratigraphy and tectonics of Death Valley — a review

    NASA Astrophysics Data System (ADS)

    Knott, J. R.; Sarna-Wojcicki, A. M.; Machette, M. N.; Klinger, R. E.

    2005-12-01

    New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from > 3.58 Ma to < 1.1 ka. These tephra beds and tuffs establish relations among the Upper Pliocene to Middle Pleistocene sedimentary deposits at Furnace Creek basin, Nova basin, Ubehebe-Lake Rogers basin, Copper Canyon, Artists Drive, Kit Fox Hills, and Confidence Hills. New geologic formations have been described in the Confidence Hills and at Mormon Point. This new geochronology also establishes maximum and minimum ages for Quaternary alluvial fans and Lake Manly deposits. Facies associated with the tephra beds show that ˜3.3 Ma the Furnace Creek basin was a northwest-southeast-trending lake flanked by alluvial fans. This paleolake extended from the Furnace Creek to Ubehebe. Based on the new stratigraphy, the Death Valley fault system can be divided into four main fault zones: the dextral, Quaternary-age Northern Death Valley fault zone; the dextral, pre-Quaternary Furnace Creek fault zone; the oblique-normal Black Mountains fault zone; and the dextral Southern Death Valley fault zone. Post - 3.3 Ma geometric, structural, and kinematic changes in the Black Mountains and Towne Pass fault zones led to the break up of Furnace Creek basin and uplift of the Copper Canyon and Nova basins. Internal kinematics of northern Death Valley are interpreted as either rotation of blocks or normal slip along the northeast-southwest-trending Towne Pass and Tin Mountain fault zones within the Eastern California shear zone.

  7. Late Miocene-Pleistocene Stability of upper Ferrar Glacier, Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Staiger, J. W.; Marchant, D. R.; Schaefer, J. M.; Johnson, J. V.; Oberholzer, P.

    2005-12-01

    Vernier Valley (78o S, 161o E) opens onto a peripheral lobe of upper Ferrar glacier in the Dry Valleys of southern Victoria Land, Antarctica. The areal distribution of Ferrar drifts, along with a relative and numerical chronology afforded by surface-weathering characteristics and 3He - 21Ne exposure-age data, are used to reconstruct the Late Miocene-to-Pleistocene history of upper Ferrar Glacier. Applying a modest erosion rate correction of 10 cm Ma-1, our results show that the glacial record provided by Ferrar (1, 2, 3, and 4) drifts in Vernier Valley extends back into late Miocene time. Cosmogenic ages for clasts on the modern, ice-cored Ferrar 1 moraine suggest that nuclide inheritance is negligible. The development of weathering pits and desert varnish on surface cobbles varies linearly with cosmogenic age. Ice-surface profiles reconstructed from the moraine distribution and exposure-ages of boulders atop the moraines indicate that the ice-surface elevation of upper Ferrar Glacier has lowered roughly 50 m throughout the Quaternary Period and roughly 125 m since late Miocene time. Conversely, during MIS 2, the ice-surface elevation of upper Ferrar Glacier was likely no higher than today and may have been below modern levels. The moraine now forming through ice sublimation and debris accumulation at the modern, cold-based Ferrar Glacier margin is texturally similar to older drifts up-valley. The slow recession of cold-based glacier ice (and without surface melting ablation zones) in lower Vernier Valley implies enduring cold-desert conditions, much like those of today, for at least the last ~6.5 Ma. Results from a 2-D glacier flow-band model also demonstrate that upper Ferrar Glacier lacked basal-melting zones even during the Pliocene optimum. The overall stability of this glacial system has implications for the response of ice in this sector of Antarctica to future polar warming.

  8. Structure of the San Fernando Valley region, California: implications for seismic hazard and tectonic history

    USGS Publications Warehouse

    Langenheim, V.E.; Wright, T.L.; Okaya, D.A.; Yeats, R.S.; Fuis, G.S.; Thygesen, K.; Thybo, H.

    2011-01-01

    Industry seismic reflection data, oil test well data, interpretation of gravity and magnetic data, and seismic refraction deep-crustal profiles provide new perspectives on the subsurface geology of San Fernando Valley, home of two of the most recent damaging earthquakes in southern California. Seismic reflection data provide depths to Miocene–Quaternary horizons; beneath the base of the Late Miocene Modelo Formation are largely nonreflective rocks of the Middle Miocene Topanga and older formations. Gravity and seismic reflection data reveal the North Leadwell fault zone, a set of down-to-the-north faults that does not offset the top of the Modelo Formation; the zone strikes northwest across the valley, and may be part of the Oak Ridge fault system to the west. In the southeast part of the valley, the fault zone bounds a concealed basement high that influenced deposition of the Late Miocene Tarzana fan and may have localized damage from the 1994 Northridge earthquake. Gravity and seismic refraction data indicate that the basin underlying San Fernando Valley is asymmetric, the north part of the basin (Sylmar subbasin) reaching depths of 5–8 km. Magnetic data suggest a major boundary at or near the Verdugo fault, which likely started as a Miocene transtensional fault, and show a change in the dip sense of the fault along strike. The northwest projection of the Verdugo fault separates the Sylmar subbasin from the main San Fernando Valley and coincides with the abrupt change in structural style from the Santa Susana fault to the Sierra Madre fault. The Simi Hills bound the basin on the west and, as defined by gravity data, the boundary is linear and strikes ~N45°E. That northeast-trending gravity gradient follows both the part of the 1971 San Fernando aftershock distribution called the Chatsworth trend and the aftershock trends of the 1994 Northridge earthquake. These data suggest that the 1971 San Fernando and 1994 Northridge earthquakes reactivated portions of

  9. Preliminary Geologic Map of the Southern Funeral Mountains and Adjacent Ground-Water Discharge Sites, Inyo County, California, and Nye County, Nevada

    USGS Publications Warehouse

    Fridrich, Christopher J.; Thompson, Ren A.; Slate, Janet L.; Berry, M.E.; Machette, Michael N.

    2008-01-01

    This map covers the southern part of the Funeral Mountains, and adjacent parts of four structural basins - Furnace Creek, Amargosa Valley, Opera House, and central Death Valley. It extends over three full 7.5-minute quadrangles, and parts of eleven others - a total area of about 950 square kilometers. The boundaries of this map were drawn to include all of the known proximal hydrogeologic features that may affect the flow of ground water that discharges from the springs of the Furnace Creek wash area, in the west-central part of the map. These springs provide the major potable water supply for Death Valley National Park.

  10. Geologic map of the Lockwood Valley Quadrangle, Ventura County, California

    USGS Publications Warehouse

    Kellogg, Karl S.

    2001-01-01

    The Lockwood Valley quadrangle is located in the western Transverse Ranges of California, about 10 km southwest of Frazier Park. It includes the western flank of Frazier Mountain, southern Lockwood Valley, and a region of the Los Padres National Forest near northern Piru Creek. The oldest rocks are mostly biotite augen gneiss, in the hanging wall of the Frazier Mountain thrust and in a large body south of the thrust. A U-Pb zircon age for the gneiss is 1690+5 Ma (W. Premo, unpublished data). Two Cretaceous intrusive rocks are named the quartz monzonite of Sheep Creek and the coarse-grained granodiorite of Lockwood Peak. A U-Pb zircon age on the latter is 76.05+0.22 Ma (W. Premo, unpublished data). The northeastern edge of a large Eocene marine basin, comprising the sandstones, shales, and conglomerates of the Juncal Formation, occupies the southwestern 25 percent of the quadrangle. Miocene fluvial rocks, including coarse boulder conglomerates, sandstones, and shale, of the Caliente Formation crop out mostly in the northwestern part of the quadrangle. Commercially exploitable Lockwood Clay unconformably overlies the Caliente, which, in turn, is overlain by the mostly fluvial Pliocene Quatal Formation. Two major south-directed thrusts, the Frazier Mountain thrust and the South Frazier Mountain thrust, place crystalline rocks over Miocene and Pliocene sedimentary rocks. The South Frazier Mountain thrust is transected by the newly recognized, north-directed Lockwood Peak reverse fault. In addition, the newly recognized south-directed Yellowjacket thrust displaces rocks of the Pliocene Quatal Formation.

  11. Integrated exploration workflow in the south Middle Magdalena Valley (Colombia)

    NASA Astrophysics Data System (ADS)

    Moretti, Isabelle; Charry, German Rodriguez; Morales, Marcela Mayorga; Mondragon, Juan Carlos

    2010-03-01

    The HC exploration is presently active in the southern part of the Middle Magdalena Valley but only moderate size discoveries have been made up to date. The majority of these discoveries are at shallow depth in the Tertiary section. The structures located in the Valley are faulted anticlines charged by lateral migration from the Cretaceous source rocks that are assumed to be present and mature eastward below the main thrusts and the Guaduas Syncline. Upper Cretaceous reservoirs have also been positively tested. To reduce the risks linked to the exploration of deeper structures below the western thrusts of the Eastern Cordillera, an integrated study was carried out. It includes the acquisition of new seismic data, the integration of all surface and subsurface data within a 3D-geomodel, a quality control of the structural model by restoration and a modeling of the petroleum system (presence and maturity of the Cretaceous source rocks, potential migration pathways). The various steps of this workflow will be presented as well as the main conclusions in term of source rock, deformation phases and timing of the thrust emplacement versus oil maturation and migration. Our data suggest (or confirm) The good potential of the Umir Fm as a source rock. The early (Paleogene) deformation of the Bituima Trigo fault area. The maturity gap within the Cretaceous source rock between the hangingwall and footwall of the Bituima fault that proves an initial offset of Cretaceous burial in the range of 4.5 km between the Upper Cretaceous series westward and the Lower Cretaceous ones eastward of this fault zone. The post Miocene weak reactivation as dextral strike slip of Cretaceous faults such as the San Juan de Rio Seco fault that corresponds to change in the Cretaceous thickness and therefore in the depth of the thrust decollement.

  12. 78 FR 30965 - AG Valley Railroad, LLC-Operation Exemption-Ag Valley Holdings, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-23

    ... Surface Transportation Board AG Valley Railroad, LLC--Operation Exemption--Ag Valley Holdings, LLC AG... original and 10 copies of all pleadings, referring to Docket No. FD 35736, must be filed with the Surface.... Board decisions and notices are available on our Web site at www.stb.dot.gov . Decided: May 20, 2013....

  13. Origin of the Valley Networks On Mars: A Hydrological Perspective

    NASA Technical Reports Server (NTRS)

    Gulick, Virginia C.

    2000-01-01

    The geomorphology of the Martian valley networks is examined from a hydrological perspective for their compatibility with an origin by rainfall, globally higher heat flow, and localized hydrothermal systems. Comparison of morphology and spatial distribution of valleys on geologic surfaces with terrestrial fluvial valleys suggests that most Martian valleys are probably not indicative of a rainfall origin, nor are they indicative of formation by an early global uniformly higher heat flow. In general, valleys are not uniformly distributed within geologic surface units as are terrestrial fluvial valleys. Valleys tend to form either as isolated systems or in clusters on a geologic surface unit leaving large expanses of the unit virtually untouched by erosion. With the exception of fluvial valleys on some volcanoes, most Martian valleys exhibit a sapping morphology and do not appear to have formed along with those that exhibit a runoff morphology. In contrast, terrestrial sapping valleys form from and along with runoff valleys. The isolated or clustered distribution of valleys suggests localized water sources were important in drainage development. Persistent ground-water outflow driven by localized, but vigorous hydrothermal circulation associated with magmatism, volcanism, impacts, or tectonism is, however, consistent with valley morphology and distribution. Snowfall from sublimating ice-covered lakes or seas may have provided an atmospheric water source for the formation of some valleys in regions where the surface is easily eroded and where localized geothermal/hydrothermal activity is sufficient to melt accumulated snowpacks.

  14. Volcano-Tectonic Evolution of the Central Death Valley Volcanic Field - Insights Derived from the Geologic Map of the Death Valley Junction 30' x 60' Quadrangle

    NASA Astrophysics Data System (ADS)

    Thompson, R. A.; Fridrich, C.; Chan, C. F.; Zellman, K. L.; Workman, J. B.

    2014-12-01

    The geologic map of the Death Valley Junction 30' x 60' quadrangle encompasses many geologic features recording the Cenozoic volcano-tectonic evolution of central Death Valley. Most notable is the central Death Valley rhombochasm. The rhombochasm is a 65x80-km rhombic pull-apart basin complex that occupies the releasing step-over between the northern Death Valley—Furnace Creek and southern Death Valley faults. Stewart (1983) documented this feature by palinspastically restoring offset thrust fault segments and isopachs, thereby closing the rhombochasm. The central Death Valley volcanic field records the coincident and related magmatism that occurred during the extension and strike-slip strain that formed the rhombochasm. In the multi-stage evolution of this tectonomagmatic feature, changes in volcanic and structural styles, rates, and loci were synchronized, both spatially and temporally. The volcanic field covers an area of 3600 km2, and consists of >700 km3 of lava flows, domes, and pyroclastic deposits. Cenozoic map units reflect four major eruptive stages: Stage 1 (11-9 Ma: rhyolite and andesite), Stage 2 (9-7.5 Ma: dacite>basalt>andesite), Stage 3 (7-5 Ma: dacite>basalt), and Stage 4 (4.5-0.7 Ma: basalt). The predominant loci of eruptive centers migrated northwestward during this volcanic evolution, coeval with northwestward migration of adjacent depocenters. Stage 1 and 2 volcanism is broadly correlative to the supradetachment stage of rhombochasm development. Related intrusions include exposed upper-plate hypabyssal and lower-plate plutonic bodies. Stage 3 and 4 volcanism occurred during two tectonic stages in which higher-angle faults cut across the detachment fault, forming basins that are nested within the original detachment-floored area of the rhombochasm. Time-transgressive changes from dominantly silicic and intermediate magmas in Stages 1 and 2 to dominantly mafic and lesser intermediate magmas in Stages 3 and 4 coincided with decreases in eruptive

  15. Active mantle flow and crustal dynamics in southern California

    NASA Astrophysics Data System (ADS)

    Fay, N.; Bennett, R.; Spinler, J.

    2007-12-01

    We present numerical modeling analysis of active upper mantle flow and its role in driving crustal deformation in southern California. The forces driving lithospheric deformation at tectonic plate boundaries can be thought of as the sum from two sources: (1) forces transmitted from the far-field by rigid tectonic plates, and (2) forces created locally at the plate boundary by heterogeneous density distribution. Here we quantify the latter by estimating the stresses acting on the base of the crust caused by density-driven flow of the upper mantle. Anomalous density structure is derived from shear wave velocity models (Yang & Forsyth, 2006) and is used to drive instantaneous incompressible viscous upper mantle flow relative to a fixed crust; this allows isolation of stresses acting on the crust. Comparison of results with the finite element codes Abaqus (commercial) and GALE (community- developed) is good. We find that horizontal tractions range from 0 to ~3 MPa and vertical tractions range between approximately -15 to 15 MPa (negative indicating downward, positive upward); Absolute magnitudes depend on the assumed velocity-density scaling relationship but the overall patterns of flow are more robust. Anomalous density beneath the Transverse Ranges, in particular beneath the San Bernardino Mountains and offshore beneath the Channel Islands, drives convergent horizontal tractions and negative vertical tractions on the base of the crust there. Anomalous buoyancy beneath the southern Walker Lane Belt and anomalous density beneath the southern Great Valley create a small convective cell (the Sierra Nevada "drip"), which promotes extension on the eastern edge of the Sierra Nevada block and subsidence of the Great Valley. Favorable comparison with contemporary crustal thickness, heat flow, and surface strain rate indicates that upper mantle flow plays a very important role in active crustal deformation in southern California and much of the non-ideal behavior of this

  16. Using Groundwater Temperatures and Heat Flow Patterns to Assess Groundwater Flow in Snake Valley, Nevada and Utah, USA

    NASA Astrophysics Data System (ADS)

    Masbruch, M. D.; Chapman, D. S.

    2009-12-01

    The Southern Nevada Water Authority’s (SNWA) proposal to develop groundwater resources in Snake Valley and adjacent basins in eastern Nevada has focused attention on understanding the links between basin-fill and carbonate aquifer systems, groundwater flow paths, and the movement of groundwater between basins. The SNWA development plans are contentious in part because (1) there are few perennial streams that flow into the basins and these surface-water resources are fully appropriated; (2) groundwater resources that sustain streams, springs, wetlands, and the local agricultural economy are also limited; and (3) because Snake Valley straddles the Utah-Nevada state line. We report groundwater temperatures and estimates of heat flow used to constrain estimates of groundwater flow into and through Snake Valley. Thermal logs have been collected from 24 monitoring wells in the Utah part of the valley. Natural, undisturbed geothermal gradients within the Basin and Range are generally 30 °C/km, which correspond to heat flow values of approximately 90 mW/m2. Geothermal gradients in the southern portion of Snake Valley are lower than typical Basin and Range geothermal gradients, with the majority ranging between 10 and 20 °C/km, corresponding to heat flow values of 30 to 60 mW/m2. In the northern portion of the basin, however, geothermal gradients are generally higher than typical Basin and Range geothermal gradients, with thermal logs of two wells indicating gradients of 39 °C/km and 51 °C/km, which correspond to heat flow values of approximately 117 and 153 mW/m2, respectively. These observations suggest heat is being redistributed by groundwater flow to discharge points in northern Snake Valley. This interpretation is also supported by spring temperatures in northern Snake Valley and at Fish Springs National Wildlife Refuge to the northeast that are higher than ambient (12 °C) surface temperature. These thermal data are being used together with water levels and

  17. Thermal studies of Martian channels and valleys using Termoskan data

    NASA Astrophysics Data System (ADS)

    Betts, B. H.; Murray, B. C.

    1994-01-01

    The Termoskan instrument on board the Phobos '88 spacecraft acquired the highest spatial resolution thermal infrared emission data ever obtained for Mars. Included in the thermal images 2 km/pixel, midday observations of several major channel and valley systems including significant portions of Shalbatana, Ravi, Al-Qahira, and Ma'adim Valles, the channel connecting Valles Marineris with Hydraotes Chaos, and channel material in Eos Chasma. Termoskan also observed small portions of the southern beginnings of Simud, Tiu, and Ares Valles and some channel material in Gangis Chasma. Simultaneous broadband visible reflectance data were obtained for all but Ma'adim Vallis. We find that most of the channels and valleys have higher thermal inertias than their surroundings, consistent with previous thermal studies. We show for the first time that the thermal inertia boundaries closely match flat channel floor boundaries. Also, buttes within channels have inertias similiar to the plains surrounding the channels, suggesting the buttes are remnants of a contiguous plains surface. Lower bounds on typical channel thermal inertias range from 8.4 to 12.5 (10-3 cal cm-2 s-1/2/K) (352 to 523 in SI units of J m-2 s-1/2/K). Lower bounds on inertia differences with the surrounding heavily cratered plains range from 1.1 to 3.5 (46 to 147 SI). Atmospheric and geometric effects are not sufficient to cause the observed channel inertia enhancements. We favor nonaeolian explanations of the overall channel inertia enhancements based primarily upon the channel floors' thermal homogeneity and the strong correlation of thermal boundaries with floor boundaries. However, localized, dark regions within some channels are likely aeolian in nature as reported previously. Most channels with increased inertias have fretted morphologies such as flat floors with steep walls. Eastern Ravi and southern Ares Valles, the only major channel sections observed that have obvious catastrophic flood bedforms, do not

  18. Valley polarization in Si(100) at zero magnetic field.

    PubMed

    Takashina, K; Ono, Y; Fujiwara, A; Takahashi, Y; Hirayama, Y

    2006-06-16

    The valley splitting, which lifts the degeneracy of the lowest two valley states in a SiO(2)/Si(100)/SiO(2) quantum well, is examined through transport measurements. We demonstrate that the valley splitting can be observed directly as a step in the conductance defining a boundary between valley-unpolarized and -polarized regions. This persists to well above liquid helium temperature and shows no dependence on magnetic field, indicating that single-particle valley splitting and valley polarization exist in (100) silicon even at zero magnetic field.

  19. Triton's Southern Hemisphere

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This polar projection of Triton's southern hemisphere provides a view of the southern polar cap and bright equatorial fringe. The margin of the cap is scalloped and ranges in latitude from +10 degrees to -30 degrees. The bright fringe is closely associated with the cap's margin; from it, diffuse bright rays extend north-northeast for hundreds of kilometers. The bright fringe probably consists of very fresh nitrogen frost or snow, and the rays consist of bright-fringe materials that were redistributed by north-moving Coriolis-deflected winds.

  20. Preliminary Analytical Results for Ash and Burned Soils from the October 2007 Southern California Wildfires

    USGS Publications Warehouse

    Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd; Kokaly, Raymond F.; Hageman, Philip; Eckberg, Alison; Meeker, Gregory P.; Adams, Monique; Anthony, Michael; Lamothe, Paul J.

    2007-01-01

    Overview The U.S. Geological Survey (USGS) collected ash and burned soils from about 28 sites in southern California wildfire areas (Harris, Witch, Ammo, Santiago, Canyon and Grass Valley) from Nov. 2 through 9, 2007 (table 1). USGS researchers are applying a wide variety of analytical methods to these samples, with the goal of helping identify characteristics of the ash and soils from wildland and suburban burned areas that may be of concern for their potential to adversely affect water quality, human health, endangered species, and debris-flow or flooding hazards. These studies are part of the Southern California Multi-Hazards Demonstration Project, and preliminary findings are presented here.